USB-C port not working for MacBook Air M1

Do another verification: Go to about this mac, system report and check the port info and see what the status read out is on the port with the issue (does it even recognize the port?). Also please restart your Mac in safe mode and test the ports again:

How to Boot into Safe Mode on Apple Silicon Macs

1. If your Mac is powered on, shut it down ( menu -> Shut Down).
2. Turn on your Mac and continue to press and hold the power button until you see the startup options window.
3. Select your startup disk.
4. Press and hold the Shift key, then click Continue in Safe Mode.
5. Then test your ports for connectivity
6. If they work then restart normally and check again
7. Let us know the outcome

On an M1 Mac, If the internal SSD is corrupted, primarily the firmware/recovery partition, you cannot boot the M1 Mac period. The M1 Macs no longer have a firmware/recovery boot in hardware. So, if that partition is corrupted or the SSD itself is dead, the Mac itself is dead. The only exception could possibly be and external USB installer drive. In which case you could possibly reinstall macOS from it and possibly solve the issue.

Other than that, assuming the SSD itself is not dead, it is possible to fix the firmware/recovery partition with a second Mac and Apple Configurator2. It can do a "Revive" which will install the most current firmware/recovery partition. It may also be necessary to do a full Restore which wipes everything from the drive, i.e. all data lis lost.

Also, aside from an Apple Store, there could be an Authorized Apple Service Provider that is closer. Not knowing where you are, you can contact the Apple support number most appropriate for your location her :Contact Apple for support and service - Apple Support to find out if there is one close by.

You can ship it for repair.

How do you know it's not working? If only one external device has "failed" try another. Or a different cable if one is used. It may be a hardware issue; devices don't fail on a known schedule. Big Sur may be the cause, but it might also be a Big Sur hardware incompatibility problem.

Without full details and a more complete description of what's going on, assistance is difficult.

I am having the same issues where as the back left works on my 2019 Macbook Pro, but the front left will only support charging. I had diagnostics run at the Apple store and they said the hardware is fine. Absolutely a software issue.

No Bueno on any of the suggested steps 1) SMC Reset 2) NVRAM Reset 3) Safe mode boot.

It was suggested to me (by the apple store) that I wipe my computer and restore to factory settings by that seems like an absolute overkill. Let me know if you have found any luck restoring your usb-c ports.