Flags in Mail won't go away

Hello. The only solution I've seen to this is rebuild the mailboxes, which didn't work. How to get rid of flags when messages are deleted but flags remain? https://preview.redd.it/99rjlv4fi07e1.png?width=261&format=png&auto=webp&s=35b87d8f0a7e57c7c2c90d7c12c3a7d3aa9f2513