Had the same problem after joining from yellow telco. What i did:
1. Restore my iPhone.
2. Set as new ( do not restore from backup)
3. Set everything up EXCEPT your Apple ID. Do not Sign in. Just leave it blank
4. Once finished, go to settings > messages > tick on iMessage. After that click “sign imessage with your Apple ID”. Just type in your Apple ID and password
5. Go to Facetime, tick on FaceTime and also click “sign in with your Apple ID”
6. Test whether it work or not
Ouch. Easier said than done. But, I’ll give it a try, once I have the time to. Setting up everything to the way it is now gonna take a lot of time. Thanks, man!