My iPhone number keeps appearing deregistered

i'm not sure what is going on. when i got my iphone 14 pro max this fall i started having an odd problem syncing messages between my ipad 12 pro max and this new phone. i am pretty familiar with the "not syncing between devices" issue and have been able to solve it was deleting a conversation and such and re-logging in to imessage or whatever.

So occasionally i send myself links via imessage because i want to open it on a larger screen instead or because i happen to have it open on ipad and want to take it with me on my phone.

for this purpose I have a chat open on my device with myself. When i got the phone right away when it was available this past october, i started having a strange issue with my phone thinking it had to send messages to my own number as text (green) but not imessage. iP ad usually doesn't have this problem. i send a test message from ipad and this seems to refresh temporarily and it will show blue between phone and iPad no matter which device is sending.

usually this only lasts a few minutes before my phone forgets and it turns green again when sending from the phone.

i have turned iMessage on and off on both devices, logged out of my apple id on both, restarted devices... all of these only have a short success time.

I also noticed that I was not able to start new conversations from my phone number on my phone in the settings. But it was sad that way in the iPad settings. and my phone number was selected for receiving and replying to convos on both.

i have just tried turning off imessage on both, deleting the convo on both, (also one group iphone family chat that was refusing to sync day old messages) and restarting phone then turning it back on and restarting the convos.

still doing it, this is a convo with my own number and it's also very slow to sync with my ipad now again after working just fine for a few minutes.

[Re-Titled by Moderator]