iPhone 13 mini cellular network works temporarily then stops

Hi everyone, I'm having an intermittent cellular network issue with my iPhone 13 mini. The signal works temporarily but then stops working completely.

I've already tried several troubleshooting steps, including:

- Restarting the phone

- Updating the OS to the latest version

- Checking for carrier settings updates

- Reseating the SIM card in the tray

- Testing with a known-working SIM card

- Resetting the Network Settings

After performing these steps, the network will work for a short period before dropping out again. I'm starting to suspect a hardware issue, possibly related to the logic board (sandwich board separation) or an internal antenna connection.

Has anyone else experienced this specific behavior, and what was the ultimate fix? Does this sound like a common hardware failure for this model?

Thanks!