u/Expert-Brain7258

I transferred my sim card to my iPhone 16 Pro Max around 5 days ago. During that time, iMessage and FaceTime were working fine. But suddenly yesterday it says that there has been an activation error. When I check, the "you can receive iMessages to and reply from" portion gives out the completely wrong number.

I've checked cellular > My Number and it is the correct number. I've tried restarting my phone, re-inserting my sim card, resetting network settings, all have failed me. Apple support for some reason has not returned back to me. I’m in the most recent ios version which for me rn is ios 26.5

How do I fix this?