Google and carriers deployed changes to RCS which have been breaking it for many users on the stock OS including with certain carriers and in whole countries. The changes appear to have specifically impacted GrapheneOS users too. It's not related to our September 8th update. We're working on it.
You can find many recent threads about people having issues with RCS in Google Messages while using a stock OS with Google Mobile Services. There are articles about how some carriers and countries no longer have it. It still works for most people but the changes definitely regressed compatibility.
GrapheneOS users were impacted by these recent changes much more than other users. We don't know why yet but we're working on determining that and restoring compatibility with Google Messages for people who use it. We'll try to get compatibility with the new way it functions implemented very soon.

@GrapheneOS

10 bucks on one of the components you stripped of permissions was used to dynamically pull in code that made it continue to work on the non-affected stock os devices.

@agowa338 The changes also broke it for many users on stock Google Mobile Services operating systems.

@GrapheneOS

"many != all". If there wasn't something different than it would either affect all of them or none...

Let us know when you discovered what fuckery they did this time and we'll know for sure.

I'd just expect it being something dynamically pulled from external that causes the the ones that still work to not have failed too at this point...

@agowa338 @GrapheneOS it broke for samsungs as well, my partner's phone normally does RCS by default, and he was asking me what the "RCS failed, delivered over SMS" messages he kept getting are. i just turned RCS off on his phone. I dont think samsung strips permissions for its messaging app, but it definitely adds and expands upon default google messages

@RetroRelics @GrapheneOS

GrapheneOS said it is something done in tandem with the carriers. So it could also be that it's the combination of device and carrier or something.

But so far that was just a dystopian guess from my side. Let's see what they discover and what actually caused this.