I've tried all the re-indexing processes , even did a Mac OS re-install (but unfortunately it drops down 12.1 still) and none of these solutions work. Hopefully MS or Apple give us an update soon!

And ...New Outlook is not a solution , it is a mess in itself...the mind boggles that MS can make a version of Outlook that doesn't support exchange accounts never mind the "on computer" folders that are in effect the "PST's"

Tried that yesterday , with no luck at all.

Downloaded the new OS Beta 12.2 Beta (21D5025f) that came out just now . Busy reindexing Spotlight (Moving Macintosh HD to Private then out in the spotlight preferences) and waiting the reindexing to complete. I do see some searches in outlook bringing results , so hopefully once the indexing is complete this may work..

So installing Monterey 12.2 Beta 1 didn't solve the issue , did all the reindexing etc.

Regarding the Outlook Search / Monterey 12.1 issue , I tried the new Outlook Beta 16.57.21122200 released today but I don't think this address the issue as I still get no result even after moving Main Profile in and out of Spotlight Privacy . I cannot see the release notes as yet on the MS Outlook beta release notes page as yet.

And New Outlook does not support "on computer" folders either..

I have just downloaded Ventura Beta 4 and done a full Spotlight Reindex and the problem remains....I've reported to both Apple and Microsoft. I am running the latest beta of MS Outlook also (16.64 (22072501))