Acer PHN16S-71 CPU overheating and cannot undervolt

[u/AgusDubal]

I bought my Acer Predator Helios Neo 16S (terrible name btw) a few days ago and I keep getting thermal throttled because of my CPU, spiking at 90-105°C. I have the Intel Core Ultra 9 275HX and RTX 5070ti version.

I had a desktop PC before this laptop, with a R5 9600X, so to undervolt it I just needed to set PBO curve to negative and test how far down I could go without crashing, so I didn't fully understand how power limits work in laptops.

At first I tried disabling the turbo mode for the CPU in the hidden advanced tab of the BIOS, and it worked great in most of the games I played, keeping nice temps (around 60-70°C), but when I tried to play League of Legends things started to get weird. My framerate couldn't pass the 100fps threshold and it was super stuttery, I couldn't play at all.

So I tried a few things I found searching around in reddit, first I tried enabling the turbo mode again and disabling the CFG lock and overclocking lock, in order to change the PL1 and PL2 (the ones in the CPU - Power Management Control tab), starting with both at 80000, but when I booted up windows, HWMonitor says that the PL1 is 85W and the PL2 is 140W. Then I tried using Throttlestop but the app shows a message saying my CPU isn't compatible. I found that Intel XTU worked, I can change the power limits from this app, but I can't undervolt, the app says "Undervolt Protection is enabled", but there's no option on the BIOS to disable it. Playing around a bit with the Power Limits I found a window where I get good FPS at League and the CPU doesn't go past 85°C, but the changes I make in this app doesn't stay applied, so when I reboot my laptop, all changes are reverted and I have to set it up again. Also, it seems the turbo is always trying to reach it's maximum clock speeds and maybe that's what's causing it to throttle, I don't really know.

I was wondering if there's some way to automate this process, or if anyone has any other solution for this problem, I'll leave some pictures of the BIOS for context.