I came to the forums to see if I could find anyone else having the same issue, and sure enough, I found a bunch!
Got my mother an S20 FE and she has had nothing but problems with it. Calls don’t come through, texts are delayed by hours or don’t send or deliver at all. It is intermittent and completely random. Samsung says it is a T-Mo signal problem. Unacceptable for a 74 year old woman who lives alone to not have a reliable device or service.
I had her switch to LTE/3G/2G network mode and we’ll see how that works. There’s no reason the service should not work as intended on the 5G/LTE/3G/2G mode. This is a new phone from T-Mo with the latest 5G SIM. Regardless if there is 5G service in the area or not, people should not be having these issues. It needs fixed!