Me and my dad both have a S21. two days ago, his phone cant make nor receive call, but can still use data. When I tried to make a call using his phone, the call just ends right away as if there is no signal, but I checked the signal as well as airplane mode, nothing seems wrong. I also restarted the phone. The weirdest thing is that when I switched the sim card (plug in my sim card into his phone and his card into my phone), both number works, but when I switched it back, my number still works while his doesn't. Anyone knows what this could be?
Yes, definitely check with the carrier and have the SIM replaced. If he stays at home a lot and is mostly connected to wi-fi, I recommend turning on airplane mode with wi-fi and using wi-fi calling if you can't get to a carrier store right away.
