Solved! Go to Solution.
I have had the same issue with my s20/tmobile since the summer.
It seems to go into a secret airplane mode without any notice (no texts, calls, messages, etc.).
It also sends and revcives duplicates of texts up to 6 times.
T-Mobile sent me a new sim card and that seems to have helped, but still getting muliple texts and unable to send and recieve texts from time to time.
It is so frustrating and am also thinking of switching to an iphone for the first time ever!
Not the behavior I'd expect from a flagship phone...