iPhone 13 Pro Cellular Issue

Hi everyone,

my iPhone 13 Pro is currently displaying some strange behaviour and I don’t know what I should do.

A couple of days ago, my cellular connection broke down (no calls/no data) and the iPhone either displayed a constant “searching” animation in the connection strengt bars or straight up displayed the triangle with exclamation mark.

In the settings under “Mobile Service” it just says “Error” and if I access it, the message “An update is required to use mobile data on this iPhone” is displayed.

I have tried every fix that I could find on the internet (airplane mode, network settings, sim card, hard reset etc) but nothing has helped so far.

It has nothing to do with my provider or my SIM card, since I have changed providers without success and the card works fine with another iPhone.

Strange is, that if I turn the iPhone off and on a couple of times the connection comes back and stays for some time (sometimes 15 minutes and sometimes a day) but always crashes again.

Diagnostics are not showing any errors with software or components so I am at a total loss.

I would greatly appreciate any help or tips that would give me another option to try myself before sending the phone back to Apple.

Many thanks in advance.