Hello,
i have set the option for emails to be marked as read after 1 second.
With the update to 11 (11.0.1389), on both windows and osx machines, often times emails switch to “read” only to switch back to unread shortly after. My account is a Microsoft 365 one and switched over to Microsoft Graph.
Not sure what details i can provide to make the bug hunt easier.
cheers
Markus