Microsoft office apps not opening on first try in BigSur

Ever since I updated to Big Sur, my MS Office apps (Word, Excel, Powerpoint - all recent versions) will not open on the first try.

When I click on the app, everything freezes for about 20-30 seconds. And then I get two pop-up messages.

1. You do not have permission to open the application "Microsoft Word.app" Contact your computer admin...
2. Microsoft Word quit unexpectedly. Click report to see more detailed information (and then I can 'Ignore' or 'Report'

I typically ignore the error and close both pop-ups.

Then, when I try to open the app immediately following this, it works fine.

How do I get around this delay so it recognizes the apps the first time? Thanks!!