Mail not automatically being marked as Read in Mail (Redux)

MacOS Mail on Sonoma is not marking many messages as read (by removing the blue dot) even when I click it and click out to another message and click back, multiple times.

This happens only to some email -- seems more often to ones in threads I've flagged or that were sent to lists.

Quitting & restarting Mail "resolves" the problem.

Similar to several other closed and unresolved threads, including this one.

Resolution? Permission issue? Errant Rules (seems unlikely cuz this happens after rules presumably already applied and I don't have any marking messages as unread.) ?