I’m at home mostly and the signal bar is 2 bricks.
I usually get a text telling me I missed the call, but the phone itself never receives the call.
Tried the SIM card on a different phone, same location?
No I haven't. I could try my wife's iPhone but of course unless someone is trying to call me, I won't know and it is not all calls either.
Sometimes the phone can be in my hand as I look at stuff and I will suddenly get one of those "who called" texts and, since I was using the phone for other things, I know full well that the incoming call never showed up at all.