@Nesivos,

I’d like to suggest a couple of partial “workarounds”, instead of uninstalling and reinstalling Avast.

1_ When you try to “fix it” from the main GUI, you should reboot immediately after before concluding it isn’t fixing anything.

2_ What happens if before the backup you stop Avast service and shields? For stopping the service, I would think you would need first to disable the defense module from Avast settings → troubleshooting. Trying / testing a reboot after that and leaving Avast disabled before the backup might help?

3_ If having to uninstall and reinstall, instead you should try a simpler Repair from “Add/Remove Programs”, and then reboot immediately. Only after the reboot, check if Avast is working and if your settings were left untouched.

There might be other partial workarounds. In any case, these might be “valid” workarounds for INfrequent backups. If this is for each and every night, I would not consider these as practical workarounds and a more “clean and permanent” real solution should be found.