Oh dear. You’d need to provide more info to properly troubleshoot this - too many variables to know what could be going on. I suggest starting with a couple of older threads about similar situations and see if they might help or give clues (or rule stuff out). Take a look at:
I can no longer recieve sms messages and
Sometimes I don't receive the text messages and
Librem 5: can no longer receive SMS messages or calls and
Sending SMS messages stopped working - how to debug?
And: is everything else, like calling and mobile data working? Did something happen or did you install something?