Watch doesn't get text message and receive phone calls

I support a number of apple devices, iPhone, watches, etc. I have come across a few of them with the same issue. The watch doesn't get text message and receive phone calls. I have tried every possible solution I can think of and search for. I've checked there configurations for both watch and phone and it was correct. None of this makes any sense. They are all on the latest IOS . Some of them I had to unpair the watch and re-pair it and yes it did work , while others have told me it started working.

All the watches are Series 11, and the phones are mostly 16 & 15's .

yours truly,

Very Frustrated,