I have the same "problem" but its not really a problem!?
The reason I think is that the Script Blocking runs as Normal. If you set it to high it resets to normal upon reboot. (Remember there is only one setting for the Script Blocker). So, when everything is set to High and you reboot, Script Blocker returns to Normal thus causing Resident Protection to show as Custom!
Click on the Avast icon next to the clock to open On-Access Protection Control. Resident Protection will probably be at Custom. Click on the Details button and you will see everything is at High except for Script Blocker.
Hope this helps
