I have a same problem MB Pro 16" with M1 Max.

I have addressed the situation with Apple support and unfortunately have no good result yet. However, we have tried creating a new user on the Mac and then logging into Outlook. It downloaded all the messages and if I gave a search term during the download process, it found the messages. In this case, however, the messages seemed to be downloading to the cache So apparently the problem is that macOS does not allow access to the indexes where the emails are stored permanently. I am trying to contact Apple support again.

Problem solved! I downloaded beta version of Outlook 16.58.22010406 and it works. In Outlook: Tab ,,Help" Choose ,,Find update" Choose ,,Advanced settings" Choose ,,Beta chanel" and agree with Terms and conditions Program find new beta version and you will instal it After this you can return back to ,,Alfa chanel" and wait for next standard update. I am happy!!! And you? MacBook Pro 16" M1 Max