Program manager doesn't work properly after Win 11 update

I updated to Windows 11 yesterday and ever since, I've been experiencing a number of issues. One of these issues is more frequent program freezes - the app stops running and a "frosted" overlay appears over the app window. Eventually a notification appears asking if I want to wait or quit the app. No matter which option I choose, the result is the same - no change. When I open the Program Manager and select "End Task for the app, it does nothing - the app remains on screen and I have to shutdown my laptop in order to stop the app. Any suggestions/help is appreciated. Thanks.

Perform clean boot state to found out if any one of the startup programs or services causing the problem.