I've had my s21ultra since launch with no problems, over the past month though I've differently been getting terrible mobile phone signal. This seems to go from full bars down to 1 to a dreaded 'no service' circle icon with a line through it. Infact, the very act of trying to make a phone call or send a text sometimes kills the signal itself. Or even, it sometime tries to send me a text or can kill my signal. I've tried my sim in other phones, and tried other Sims in my phone, everything points to the phone. Tried network reset, tried loads of mobile network seeing changes, someone's switching airplane mode on and off helps for a while. It can go for a few days being really stable, then have a fit of the network going off, on, off, on, off, on etc. All that also burns down my battery pretty quickly.
Dreaded circle
😔
