Outlook 2021 not returning Search Results

I just installed Outlook 2021 on my Windows 10 machine. The same machine still has Outlook 2013 installed as well. When I do a search using Outlook 2013, results are returned properly. When I conduct the same search using Outlook 2021 I get NO results. (Both versions of Outlook are using the same .pst data file).

Notes:

This is NOT the same problem that affected searches on RECENT emails caused by Windows Update KB5008212. It also does NOT involve Windows 11. The Data file has been re-indexed and the search troubleshooter has been run but this did not fix the problem.

Any ideas as to how to fix this?