Messages missing from Mail Flagged folder

On my 2017 iMac OS 13.7.5 when I click on the Flagged folder in Mail, it shows 64 messages but no messages appear in the window, even after a very long time. I have done the following: Rebuild all mailboxes, delete all the "Envelope" files and let Mail re-import the info. I also have tried to re-index Spotlight, but that does not seem to work. I have restarted the computer several times, but am unable to get it into Safe mode. Filtering for just flagged messages in the gMail inbox shows 52 and using the web interface for gMail I see 47 messages that are "Starred." What should I try next?