I have the same issue on my phone 3 since last week. Strange. I never used RCS, don’t need to in fact as regular system worked perfectly. And everything worked fine since last week. Now i’m forced to unable RCS if I want to send MMS. So maybe there is something happening behind the scenes with operators making the transition to RCS. And of course, now it doesn’t work as perfectly as with the old protocol… It’s always the same thing. We remove what works perfectly to change to something “better” that isn’t so perfect and stable as the old one at the end.