No Network after battery died

Help Fairphone 3
1

Recently my fairphone 3’s battery died. After restarting it I no longer got any network coverage and the number on the sim card is not recognized. I restarted the phone again, toggling airplane mode, tried setting the APN, tried the Sim card in other phones (it works), reset the phone to factory settings nothing so far has helped.

I’m at a loss for what else I can try. Any ideas?

2

As you have already reset to factory settings, there is nothing to lose by trying re-installing the OS:
https://support.fairphone.com/hc/en-us/articles/18896094650513-Manually-install-Android-OS-on-your-Fairphone