Using older versions of Outlook for Mac for personal email and calendar
This worked for me. There's a "New Outlook" switch up on top blue bar to the right, once I turned that "on", it asked to restart Outlook, and the search bar was much bigger in the middle of blue bar, and started working fine!
I had the problem with Outlook 2021 (office 365 app) on Mac OSX Monterey v12.1. Hope this helps others as well.
Thanks!