I didn't update to 21.10, jumping in at 21.11 and there were two entries in the list of Apps in the Task Bar Settings. Both were enabled, but there was only one was displayed in my taskbar area.
I also noticed that my Taskbar Settings were ordered by name, yet this second Avast entry was at the bottom of this alphabetic list and was enabled/on (I switched that off). So currently I still have only one avast tray icon displayed.