I have this problem.
When I receive a message, it is “bold” (unread).
After some seconds I selected it, it becomes “not bold” (read).
Then I delete it (with canc button on keyboard), and the message is moved to dustbin folder, “not bold”.
If I change screen (selecting another window or program), and after some minutes I come back to EM client, the messages deleted before comes back to “bold” (unread status).
I have to go to dustbin folder and select them again, to change the status from unread to read.
If I want to avoid this problem, I have to do these steps.
When receive mail, selected it and wait until status change (from bold to “not bold”).
Change screen to another program.
Come back immediately to EM client and only now delete the message.
Versione of EM client: 8.1.979 (65fd04a), free version