Outlook 365 not finding mail since about second week of December 2021

I have Microsoft 365 on Windows 10 Home x64. In Outlook search has stopped finding emails I’ve received since about 12/15 2021. Anything before that is found but if I search for an email I received after that date Outlook says “No results”. I have checked indexing status and it says “Outlook has finished indexing all of your items” (see attachment). I have Search set to "All Mailboxes". It works fine for emails older than about December 15 2021 but doesn't find anything after that.

Any ideas?
Thanks,
Don