Other information that could be helpful, if you open the avastUI, Real Time Shields, the Protection status displays a wheel with all shield activity.
Checking that will give an idea of which shield is active (most) and probably the shield at issue, the individual shield icons blink as a scan is made ?
If you hover the mouse pointer over that shield icon it will display what has been scanned. It may be that a single file/location is being constantly scanned ?