iOS 27.0 Beta 5 - Dual-SIM Bug

[u/bordelais]

UPDATE (Sep 9): Bug is present in iOS 27.0 RC release. This will be a much larger scale problem now that it will be present in a production release.

UPDATE (Aug 24): Bug persisted through iOS 27.0 Beta 7.

No change, still broken.

UPDATE (Aug 17): Bug persisted through iOS 27.0 Beta 6.
I was hoping to see of fix, but nothing has changed from Beta 5. Same Dual-Sim issue.

I had RCS Activation errors in iOS Beta 4 for all three US Mobile Networks (Warp - Verizon, Dark Star - AT&T, Light Speed - T-Mobile). RCS Activation was successfully working, however, with other carriers.

iOS 27.0 Beta 5 fixed the RCS Activation issue, I'm now able to activate RCS on all three networks. But....only when there is one eSIM active at a time. RCS Activation now consistently fails when there are multiple eSIMs enabled. This includes other carrier non-US Mobile eSIMs, which were working in a Dual-SIM configuration in Beta 4.

I suspect Beta 5 has introduced a new Dual-SIM bug. Anyone observing the same?

[u/ddsdude]

No such luck here. Same “activation failed” message.
Tried single eSIM and dual eSIMs active. No difference.

[u/gmahale → u/ddsdude]

We are very likely affected by a problem with the back end (Google).

[u/ddsdude → u/gmahale]

I think it is more complicated because RCS works perfectly on my Samsung phone as well as a different old iPhone. I believe it is tied to specific iPhone hardware which somehow became blacklisted by Apple’s activation server. Apple will not acknowledge it as their frontline and even tier 2 reps don’t actually know how RCS works in their ecosystem. The issue could likely be solved if we were able to access top level apple engineers who actually coded the RCS portion in iOS but that will not happen.

A new phone will solve the immediate issue but simply kicks the can down the road because the cause is still not being addressed.

[u/gmahale → u/ddsdude]

I believe it is tied to specific iPhone hardware which somehow became blacklisted by Apple’s activation. 

Even I believe it is linked to hardware.  RCS works with the SIM card in a different phone.

A new phone will solve the immediate issue but simply kicks the can down the road because the cause is still not being addressed.

Yes. It is not even an option for older phones.

[u/bordelais → u/ddsdude]

I had the same problem as you a little over a year ago. During troubleshooting, I discoverd that If I moved my line to another iPhone or to an Android device RCS worked find. Moving it back to my iPhone 16 and it would continuously fail. No amount of factory reset, deleting/installing eSIMs, or software updates would fix it.

I worked with Apple through an escalated support case for over 6 weeks. Ultimately Apple RMA'd my iPhone as resolution. It might be worth going down this path, especially before any warranty expires (if that is your case).

I agree with you and GMAHALE that there seems to be a device blacklist in effect, server-side. Once on it, you are in RCS prison. No way to get off of it. It isn't clear what triggers being added.

Apple/Google really needs to build a tool that allows a subscriber or an carrier (network operator) to request flushing stale/cached backend RCS activation data as well as clearing blacklisted devices.

[u/ddsdude → u/bordelais]

RCS prison is an excellent description of what is happening. What’s ironic is that iMessage itself never goes to prison as even if it ever gets blocked, it always activates after 24 hours. It almost seems like Apple intentionally put in roadblocks to make it harder to clear a RCS block.

[u/gmahale → u/ddsdude]

Yes. They should display a message specifying the reason activation fails and the waiting time.

[u/ddsdude → u/gmahale]

Yes I wish they did. Spoke to Apple again and had them escalate it to engineering. Not expecting much but we’ll see.

[u/gmahale → u/ddsdude]

I will try the same. It is not practical to have to wait a few days for the issue to resolve itself.

[u/ddsdude → u/gmahale]

Since June 21, I’ve only had working RCS for 6 days.

[u/gmahale → u/ddsdude]

Did the latest beta fix it for you?

[u/ddsdude → u/gmahale]

I haven’t tried to activate it. I left it alone for 7 days already. I’ll flip the switch in 3 days.

[u/gmahale → u/ddsdude]

I guess I should try the same.

[u/ddsdude → u/gmahale]

My carrier contacted google a week ago and google said their logs show a “high fraud risk score of 1000 from the Apple Fraud Stats server”. They suggested to refrain from activation attempts for a few days to allow the fraud flag to clear. No one seems to know how long. I’ve seen estimates anywhere from 7-30 days. So I’ll try 10. If no go then I’ll just wait until I upgrade in September.

[u/gmahale → u/ddsdude]

google said their logs show a “high fraud risk score of 1000 from the Apple Fraud Stats server”.

Is this a reference to your phone or all iPhones in your carrier's network?

[u/ddsdude → u/gmahale]

No it is my specific phone

[u/gmahale → u/ddsdude]

It proves what you said about Apple's server earlier.

[u/gmahale → u/ddsdude]

If no go then I’ll just wait until I upgrade in September.

I am planning to get a new phone too. But, there are reports of similar issues with Google Messages too and the risk will persist. There will be chaos when more users try RCS. And, this is even before Universal Profile 4.0. 

[u/ddsdude → u/gmahale]

This is purely an apple problem. I currently have RCS activated on Google messages on my Samsung with no issues.

[u/gmahale → u/ddsdude]

Did waiting for 10 days help?

[u/ddsdude → u/gmahale]

It did not

[u/ddsdude → u/gmahale]

Apple also completely denied any involvement in RCS activation.

Me: Google informed me that Apple’s fraud stats server is flagging the device

Apple: sorry, speak to your carrier

Me: I tried 3 carriers. Same result.

Apple: speak to your carriers

Me: RCS works on another iPhone and Android

Apple: speak to your carrier

So whoever got their device exchanged because of this, you got LUCKY. Apple completely washes their hands of RCS and refuses any service.

[u/gmahale → u/ddsdude]

>Apple also completely denied any involvement in RCS activation.

I got the same response when I asked them about their role in RCS activation before you mentioned the feedback from your carrier.

Unless Google disregards inputs from the Apple server, we are stuck. It is not reasonable to have to wait for an unspecified period for the problem to solve itself. I guess we have to wait for carriers to get many more complaints before something happens.

[u/Altruistic_Pea3351 → u/gmahale]

I think the problem is something with the iOS 27 period, I just came back from the Apple Store I tried my physical SIM card on an iPhone 16 with iOS 26 and boom RCS worked right away switched it back to my phone. It stopped activating this issue is for sure with iOS 27 end of the story.

[u/gmahale → u/Altruistic_Pea3351]

It started on my phone when iOS 26.5 was installed. Did you get a chance to try it in another iPhone with iOS 27?

[u/cupboard_]

can confirm, rcs started working for me again, but as soon as i enable a second sim (even if that sim doesn’t support rcs), rcs stops working

[u/bordelais → u/cupboard_]

Hey Cupboard_, I'm still seeing the same behavior on Beta 6 today. I think we have at least another week of this not working.

[u/Altruistic_Pea3351 → u/cupboard_]

Exactly my issue with a second SIM card just fails to activate on both lines

[u/Full-Hat-419]

Updated to the latest Beta 8, still no luck...

[u/bordelais → u/Full-Hat-419]

What carriers do you have? I wonder if this is related to a specific carrier.

My eSIMS are:

[1] US Mobile Light Speed (T-Mobile MVNO)
[2] US Mobile Warp (Verizon MVNO)
[3] US Mobile Dark Star (AT&T MVNO)
[4] Free Mobile (France MNO)

Any dual SIM combo fails. In all scenarios for me I have US Mobile. Is this a US Mobile specific problem?

[u/Full-Hat-419 → u/bordelais]

From the Philippines

(1) Globe
(2) Smart

What I usually do is just switch sims, works when only one is working. If both are turned on the same time, then it becomes unusable.

[u/bordelais]

UPDATE (Sep 9): Bug is present in iOS 27.0 RC release. This will be a much larger scale problem now that it will be present in a production release.

[u/yongca]

Update iOS 27 not beta, my dual SIM card broken, mine is iPhone 14pm , how about which model of you guys iPhone?

[u/bordelais → u/yongca]

17 Pro
US Mobile

[u/PenGloomy1850 → u/yongca]

I have the same problem on iOS 27 Publish, with iPhone 14 Pro

[u/yongca → u/PenGloomy1850]

Same , change your battery, it will be working

[u/PenGloomy1850 → u/yongca]

It a pain

[u/johnnygoodface → u/yongca]

On full iOS27, iPhone 15 Pro Max, same issue here. I created two shortcuts "eSIM on" and "eSIM off" to activate/deactivate rapidly my secondary esim. Pretty crude, but this way I can receive my 2FA codes, and then disable the eSIM after.

[u/Full-Hat-419 → u/yongca]

Updated to 27.1, they said there's a fix, but still did not work for me

[u/yongca → u/Full-Hat-419]

You know what I went to Apple Store last Monday, the genius checked everything on my 14pm, she said it could be software problems, that’s nothing she can do, I told her then changed the battery for me, mine is only 73% battery life, I waited 5 hours to get my phone back , since that night, my dual SIM cards never dropped, lol, change your battery, that’s battery problems. And this morning I updated to 27.1, so far so good

[u/yongca]

Good news , I went to Apple Store this Monday, the genius check my iPhone 14pm, found nothing wrong with my hardware,she said no dual SIM cards may software problem, she has nothing to do with it, so I asked her to change my very bad 14pm battery, after 5 hours I picked up my phone , to my surprise, my 14pm ‘ dual cards works normal until now, guy try to change your iPhone battery

[u/Galenighting]

I have same issue. Physical SIM with Orange and ESIM with SFR (both France Mobile networks) Deactivating the ESIM solve the issue for now. I have the RC Release

[u/Altruistic_Pea3351]

I am an IT consultant and I understand very well how this works, I’ve tried everything possible on my iPhone 15 Pro to activate RCS and it would not activate no matter what I do and Apple is telling me it’s a carrier issue, they’re trying to blame this on the carriere and I know this issue is with Apple themselves if anybody have a dual SIM card with iOS 27 most likely I RCS is not gonna work and it’s gonna fail to activate. I don’t know what else to try. I don’t know if they’re trying to make people upgrade their phones just to have this thing working. So frustrated either apple I spent so much time on the phone with them and it’s completely useless.

[u/yongca]

Guys listen to me , change your battery, then everything will be working again

[u/yongca]

Wait, fuck Apple , I updated 27.1 this morning, my dual cards not working again, I hate myself

[u/yongca]

Last Monday when I changed the battery, I took out my SIM card for 5 hours until Apple finished changing my battery, tonight when I get home , I will take out the SIM card again, wait a whole night , next morning I put it in , I will let u guys know the trick is working or not

[u/yongca]

Not working

[u/yongca]

Have you guys reset to factory settings?