Samsung has **bleep** their customers with this security update issue on S20, S21, and S22 since August. It happens randomly to millions of folks. All you get is wifi calling and text. Sometimes you can get it back by having carrier do a network SIM update pushed from their end, turn off phone, wait 5 minutes, then hope you have cell connectivity again when you turn it on.
Samsung doesn't care they're trying to sell new phones so breaking millions of older ones still using UI5. I didn't have cell coverage with October and November, December got it back then January broke it again, only wifi now. February still broke, waiting now to see if March will get it back again when Verizon pushes the update soon.
My S20 Ultra has been in to service center and physically checked. It's fine, they then wiped it and reimaged it with older security update that worked before, and it started working again on cell. So it is definitely Samsung security updates breaking it. But no way to stop pushes with Verizon, so it lost it again when new update pushed. Samsung doesn't care, they won't listen when talking to them, say it's my phone, delete my posts here. So if it's not fixed soon, I'll probably be taking a step backwards from my S20 Ultra to get a Motorola. They still have SD card on some phones, but not waterproif and slower less capable. Samsung new A55 would be OK, but they said they won't sell it in US because it would eat into S23 sales being almost as capable but still has SD card. So since I have to have SD card, S20 Ultra was last good phone they sold that had it still. Good luck
2. Ship-in service. The ship-in service is approximately 7-14 days, including shipping times. A loaner device is not provided during this time. You can use the service locator link to create a ship-in service ticket or contact customer service at 1-800-726-7864.
