The customise should certainly give you options (hopefully a repair will restore that), the database reset could also help if you get full function back.
There aren’t that many things to customise from the AvastUI > Settings > Components > Software Updater settings.
Does it actually run if you launch it from the AvastUI > Protection > Software Updater ?
I have attempted the repair as suggested but it still fails.
Clicking on it in ‘Protection’ tab gives a ‘Refresh’ button, it does nothing.
If I go to settings, I get the same option as in my first post image.