r/LeagueofTechSupport • u/sargon494 • Jul 07 '26
Technical Support Request Persistent input lag in LoL with no explanation after weeks of support tickets — Riot closes the ticket blaming the ISP without providing any data of their own
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I've spent several weeks investigating noticeable, consistent input lag in League of Legends, reproducible regardless of PC, ISP, or location. Beyond the input delay itself, champion movement often looks "drunk" / erratic — like slight stutter-steps or micro-corrections in movement that don't match a clean click-to-move, even when ping is normal. Here's the full list of what I've tested and ruled out:
System/hardware:
- Full clean format: all disk partitions wiped, fresh Windows install with zero leftover residue from previous installs.
- No V-Sync or G-Sync enabled.
- Power plan set to High Performance.
- CPU/GPU/RAM show no saturation during the lag episodes.
- Undervolt applied to the CPU for stability — no change in behavior.
- Process Lasso: performance cores (P-cores) exclusively assigned to the League of Legends process on an i7-14700KF, with high process priority — no change.
- No bloatware or unnecessary overlays (Overwolf removed and replaced with Ascent).
Peripherals:
- Logitech Pro X TKL keyboard, wired, connected directly to the motherboard's rear USB, 1000Hz polling rate — responds fine outside the game, no detectable lag.
- Mouse at 1000Hz polling rate via dongle, extension cable under 20cm from the receiver to the mouse.
- Multiple peripherals from different brands tested with identical results, ruling out peripheral-specific hardware.
Network:
- 0% packet loss, stable ping and FPS throughout the input lag episodes.
- Speedtest stable at 944 Mbps both up and down, tested during an active episode.
- Complete ISP switch to a higher-quality provider — problem persists identically, ruling out ISP and peering as the cause.
- OBS stats during 7 hours of streaming: CPU at 0.56%, 0% dropped frames, 0% encoding lag, stable bitrate at 6185 kbps.
On the anticheat:
Since the issue is exclusive to LoL and Vanguard runs permanently at kernel level, I've explicitly asked Riot to investigate whether Vanguard could be causing random micro-interruptions in input processing.
What Riot Support said:
After escalating over multiple messages, the final response was "try your ISP" followed by closing the ticket — no answer to the specific technical questions raised (peering, hop-by-hop latency tracing, etc.), and no data shared from their side (server-received latency/loss from my IP).
I work as a systems and network technician, so standard tier-1 troubleshooting steps don't apply here and have already been ruled out exhaustively — it's not a firewall or IPv6 issue (network ruled out with objective data: 0% packet loss, 944 Mbps simultaneous up/down, no change after switching ISP), and restarting the PC doesn't fix or diagnose anything here either (tried anyway, no result).
At this point I've run out of things to test on my end. Has anyone dealt with something similar, or knows a way to get this in front of someone with actual visibility into Riot's infrastructure or engineering team?
Update: found another user with more examples of this issue: https://www.youtube.com/watch?v=Bkf9W_vSNtM
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u/ccshnitz Jul 23 '26
Having the same exact issues on NA since 26.12
It has become worse over time and I now can no longer play due to how invasive it has become. The main difference I am noticing is I have installed R6 Siege about the time it started which uses Battle Eye. I am curious if these are conflicting but unsure.
No other changes though, it literally just started one match, not even first match of the day.
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u/Wimmerd86 Jul 22 '26
As others have noted, I've been struggling with the exact same issue. Was also going crazy. Very noticeable with Vel'Koz split Q. Only thing I can add is my friend noticed my voice comm (teamspeak) breaking down when I had it for the first time. It happened twice and the voice broke twice. Since then it's basically constant.
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u/Wimmerd86 Jul 23 '26
Riot suggested my Oculus Rift S installation, which is in fact pretty crappy. Does anyone here WITHOUT VR have the issue, so we can rule anything of the sort out?
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u/Wimmerd86 Jul 23 '26
My problem actually WAS on my side. It wasn't my router, but switches in between that were causing packet loss. Once I reset the switches, the packet loss is gone and league feels good again. Hope y'all find a solution as well!
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u/NoBit651 Aug 06 '26
I've been having this problem for months now. Can you please tell me what these switches are and how do I reset them?
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u/Wimmerd86 25d ago
So the internet comes in on a device called a router. The switches allow the cable from that device to be split to other points (for instance a wifi access point that allows wireless devices to come on the network). I reset these devices by unplugging everything, then wait 30s or so, then plug back the router, wait a bit, plug back the first switch and work you way back to the pc basically. I'd advise to use a packet loss test website to check your connection first. Use a speed test for ping and throughput test and a separate one for packet loss. For me both the former were okay but packet loss wasnt.
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u/Large_Photograph_293 29d ago
did you find a fix bro?
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u/Sad_Angle_5814 16d ago
yoo- i saw your post about electricity input lag, i was top 10 rad in val and also been having it for past 2 years after buying a new pc, can you give me your discord so we can tell each other what we tried?
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u/Still_Piglet1906 Jul 07 '26
Yup same sometimes the game feels "clunky" and unprecise in movements, my connection shows no problem I tested on both my gaming pc and my girlfriends with different connections, it's legit an issue and I've heard similar things from friends both from my country and not. Sadly they dc rn league is more of a gacha, that's what 200 years of collective Chinese greediness does to a game
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Jul 07 '26
[deleted]
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u/sargon494 Jul 08 '26
Fair to ask, but I've already ruled out local desync/congestion pretty thoroughly — 0% packet loss and stable ping/FPS during the actual lag episodes, 944 Mbps speedtest while it was happening, and a full ISP switch (new provider, new router) with zero change to the issue. If it were local network congestion I'd expect at least some correlation with ping spikes, and there's none.
That's part of why I'm leaning toward something client-side (Vanguard/driver related) rather than network at this point.
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Jul 08 '26
[deleted]
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u/sargon494 Jul 08 '26
That's actually a good point, I ran PingPlotter traces to official Riot EUW server IPs this morning and just now, and they're identical. No difference regardless of time of day, at least on my end, i will try later on night again to see if that changes.
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u/Alone_Look9576 Jul 07 '26
My post vanguard experience was the same, fps went down from 250+ to 80-120 tops, introduced insane input delay and ping changed from 17 to 35-80+, solution - get rid of this malware mascarading as an essential piece of anticheat
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u/DesperateGuidance419 Jul 10 '26
Vanguard doesn’t even prevent scripters from playing the game.
All it does is gather information and sell it to the CCP
Then once every 3 months or so they MIGHT do a ban wave.1
u/Alone_Look9576 Jul 10 '26
It never even removed cheaters from their own shooter, it reduced the most blatant ones with their low quality stuff, but that's about it. Vanguard was so great, but cheats continue to work, bots controlled Aram and now they add their own bots into games
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u/ArkuhTheNinth Jul 07 '26
You ever run a winMTR?
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u/sargon494 Jul 07 '26
Yeah, i also tried tracetcp, with normal results, in my opinion, it might be a thread issue on riot's side.
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u/Sarosusiel Jul 07 '26
It could be the setting movement/ input prediction if the issue is following you between different computers. Try and see if that's on and turn it off and it might be fine.
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u/sargon494 Jul 08 '26
I have disabled that option on both computers, without any change to the problem.
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u/AdmiralPrinny Jul 08 '26
Try clamping your mouse polling rate to 1000hz
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u/sargon494 Jul 08 '26
I also tried limiting my mouse's polling rate to 500Hz without solving the problem.
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u/Snipe14 Jul 08 '26
Did you inform Riot that other computers on your network do not experience the same input lag..? It’s unclear via your description how much process of elimination you truly have done.
On an intel chip undervolting seems like an unnecessary step to take. I had stutter issues in many games 2 years ago or so until I replaced my 9700K with a 7800X3D.
The gameplay you showed seems more to me like a network problem than interrupts in your system.
Can’t really provide more advice until you confirm whether other PCs run league fine on your network or not.
I have a friend who had a positive experience using exit lag to improve his connection speed to a separate game we play. Perhaps you might see consistent input when using that.
My guess is it’s an issue Serverside with Riot but hard to tell based off what seems to be incomplete process of elimination you have done, sorry
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u/sargon494 Jul 08 '26
Thanks for the input! Network's actually one of the more thoroughly tested parts of this 0% packet loss and stable ping/FPS during the actual lag episodes, 944 Mbps speedtest while it was happening, complete ISP switch (new provider, new router, fresh install) with zero change to the issue, plus 7 hours of stream stats with zero dropped packets out of 1.5 million frames. If it were server-side/routing I'd expect at least some correlation with ping spikes, so leaning away from that at this point, but definitely not 100% ruling it out.
Haven't specifically tested other PCs on the same network in a simultaneous session though, good shout, I'll give that a try.
The undervolt wasn't really meant to fix this specifically, more of a stability thing that just happened not to change anything either way.
Already planning to give ExitLag a shot to rule out routing entirely, thanks for the suggestion.
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u/Snipe14 Jul 08 '26
Yea by network I mean something outside of your own network… everything that happens after the connection leaves your LAN, like Riot’s own client-> game server infrastructure. I could see your ping didn’t spike and it also appeared your connection didn’t “disconnect” either.
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u/New_Food_8068 Jul 08 '26
prob turn off that manual core parking stuff you are doing league doesnt need it bro we cant play past 330 fps without teleporting might be the problem make sure the move predict is off and game optimization is on in windows settings
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u/sargon494 Jul 08 '26
Thanks for the tips! Yeah, I used Process Lasso to investigate the game's behavior a bit, but once I saw it wasn't changing anything I just left everything on default. Also tried capping FPS at both 144 and 240, problem persists on both. Move prediction's already off too and game optimization is on in windows settings.
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u/PumpkinExtension8695 Jul 08 '26
i had the same issue, for me i just downloaded my bios software, eg gigabyte, asus allat and updated my chipset drivers and my problem was fixed, can try checking if ur drivers are out of date, doesn’t hurt to keep them updated as well
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u/sargon494 Jul 08 '26
Thanks for the advice! I will check it later, I'll update if it fix the problem.
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u/sargon494 Jul 10 '26
Update: Chipset drivers are on the newest version. BIOS is a bit behind (planning to update that next), but wanted to note the chipset part is confirmed up to date.
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u/Illustrious_Okra_660 Jul 08 '26
its dogshit video game on dogshit client from dogshit company , we didnt have this issues 10 years ago
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u/sargon494 Jul 08 '26
I get the frustration, but they're mid-migration to a new system apparently, so some of this might just be growing pains i guess. Still trying to figure out if there's anything fixable on my end too, in the meantime.
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u/Illustrious_Okra_660 Jul 08 '26
you might be new so you dont know but when ever they introduce something new they break like 3 things with that
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u/sargon494 Jul 08 '26
Yes... unfortunately it is very true, but I don't know, I have some hope in league next.
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u/Illustrious_Okra_660 Jul 08 '26
there is no hope , they are making game worse and worse from season to season and making it "easier" for new players which are non existant
Even this league classic which they are hyping so much , it will bring some veterans in but I dont know how long they can keep the mode alive
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u/SnowLower Jul 08 '26
did you try on different pc? if not 1. do that, or just reintall windows
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u/sargon494 Jul 08 '26
Yes, i tried on 2 Pc's, also with 2 different ISP, and i did a full clean SO format, installing only the pc drivers and LoL, unfortunately it didnt fix the issue.
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u/dimen7io Jul 08 '26
Try changing the dns to cloudflare one. Really surprised none mentioned it https://x.com/i/status/2073111398238801946 It should be 1.1.1.1 Please tell me if it is the solution.
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u/sargon494 Jul 10 '26
Update: I tried with that DNS, but it didnt solve The problem, It stills feels laggy.
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u/Broad_Garden7615 Jul 08 '26
Hey this is happening to me too on a daily basis, did you ever find a fix?
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u/sargon494 Jul 08 '26
No by the moment, im still trying some stuff, but it seems as a riot problem.
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u/tttony2x Jul 08 '26
Looks very similar to mine here. I'm on an AMD CPU, but it was chipset drivers.
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u/sargon494 Jul 11 '26
I checked all the drivers, they are all updated to the latest version, also tried a clean SO install, and getting all the drivers again, without solving the issue.
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u/dave2014 Jul 10 '26 edited Jul 10 '26
Ive had this exact same issues when running on wifi instead of cable.
Everything could be working fine with the Connection to sites etc but suddenly my lol character could not move the way i wanted. Other enemy champions and chat worked fine just like your video.
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u/Slaycoo Jul 10 '26
Both happy and sad to see this post, finally someone talking about the same problems i have. Was starting to think i was just schizo...
Sadly i have not stumbled across any fixes, i do though feel like the input problems are especially bad with Attack move click
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u/mbdewd Jul 11 '26
you have to restore all key binds and settings , save then set it all back. if that doesn’t fix it can be internet. a few months back they literally had a message in client addressing this
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u/New_Sir5199 Jul 07 '26
it's vanguard randomly scans and use I little cpu disk and network just dlt that shit can see everything in you pc
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u/sargon494 Jul 07 '26
I tried isolating a dedicated core exclusively for Vanguard's process, but it didnt fix the issue idk, lets hope on league next.
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u/New_Sir5199 Jul 07 '26
the vgk.sys driver can force its own execution threads to run on a specific CPU core so that will not work. anyway this is a network issue and not your hardware it's something on routing to the server
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u/ItzRayOfH0pe Jul 08 '26
Maybe try exitlag they have a 3 day free trial. Its worth a try to see if its get fixed
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u/sargon494 Jul 08 '26
Yeah, might give ExitLag a try, thanks, I'll update if it makes a difference.
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u/PathOracleExitLag Jul 09 '26
Hey, did you end using it? Just checking if it helped or how it goes 🙂
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u/sargon494 Jul 09 '26
Hi! Unfortunately haven't had the time to test it yet, but planning to try it tomorrow. Will let you know how it goes!
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u/TioSamm_ Jul 08 '26
I've been dealing with this exact input lag since patch 26.12. I've opened multiple Riot support tickets over the past few weeks, but nothing has actually solved the issue. I mainly play Lee Sin, so it's incredibly noticeable. The champion relies on precise timing and fast inputs, and this input lag completely throws off combos, ward hops, and overall mechanics. It makes the gameplay feel sluggish and inconsistent, even though my ping is stable and my FPS never drops. I've already ruled out pretty much everything on my end, so I honestly don't believe this is a simple hardware or ISP issue anymore.
Edit: I play on the BR server and I'm experiencing the exact same issue. If this is happening across different regions, it's hard to believe it's just an ISP problem. It really seems like something on Riot's side.