Have been using Avast free on High Sierra without problems and recently upgraded to OS X 10.15.7 on my 2017 MacBook Air. Avast is up to date (version 14.6). I noticed that my Finder Windows occasionally disappear (i.e., all open Finder windows) and then reappear a second or two later. The frequency of windows disappearing is not high, maybe once every minute or two, but it is nonetheless distracting. Does not happen for application windows.
The window blinking disappears if I restart in safe mode without Avast running.
I like the product and wish someone would address this problem.
