cleared flags won't disappear from the flagged section in Apple Mail

In my "Flagged" mailbox on my 2015 iMac, the various colored flag categories are listed with the associated flagged emails which are locally stored 'on my Mac' in a descriptive folder. Recently, when I un-flag or clear flags, the flag disappears but the email remains in the flagged mailbox without a flag attached. I've tried re-clearing which did nothing. I moved them back to their local mailbox which seemed to make them disappear only to have them reappear after I clicked somewhere else and then returned to the flagged category. I have closed the Mail app and reopened with no change. I shut down my computer at night and it reboots in the morning and opens Mail as a start up app. Those unflagged emails are still there. I currently have 4 unflagged emails that won't disappear that date back to Mar 20, 2025. I never had a problem prior to this.