Just posting in case other people are encountering this. My son and I both have Pixel 6 phones. A couple days ago, my son's phone stopped using RCS. The menu in Messages was missing all the options and just said that RCS was not available on the device. He tried a bunch of stuff, but eventually he "uninstalled" (removed all updates) for Messages and then re-installed the updates and it started working.
This morning, my phone suddenly switched to using SMS/MMS and when I went to the RCS Chat menu, I had the same issue. First tried just re-booting the phone which didn't help. Then did the same uninstall/update on the Messages app and everything immediately started working again.
A little frustrating since I don't know what causes the problem. I'm pretty sure RCS was working last night and possibly early this morning, but then a couple hours later it stopped. It doesn't look like there were any updates to the phone during that time?
This morning, my phone suddenly switched to using SMS/MMS and when I went to the RCS Chat menu, I had the same issue. First tried just re-booting the phone which didn't help. Then did the same uninstall/update on the Messages app and everything immediately started working again.
A little frustrating since I don't know what causes the problem. I'm pretty sure RCS was working last night and possibly early this morning, but then a couple hours later it stopped. It doesn't look like there were any updates to the phone during that time?