same issue here! Im on the latest 12.1 Monterey and the latest version of Outlook 365

Microsoft Support suggested to uninstall and re-install office..has anyone tried that? i doubt that will work..

i just noticed that ones there are new emails in outlook and you search them - you will find them, after few min they disappear from outlook search results, and you can see them only on Spotlight.. strange..

Is there a way to escalate it in MS or Apple? this is impacting business.

thank god!!! finally! new beta is solving it