K9 beta 5.734 - No outbox_state entry

I am using K9 connecting to several mailboxes also on the same mail server.
One IMAP mailbox seems to have again and again issues with the folders and how the folders are mapped.

A few weeks ago I had a similar issue with the same mailbox and only when I deleted and recreated the account in K9 receiving, sending and deleting worked.
(folders were incorrectly associated and the trash folder was missing. I could reassign some, but without trash folder deleting did not work).

At the same time Thunderbird using the mailbox also via IMAP worked without issues.

Now the outbox seems to be gone in the K9 account. It is missing in the IMAP folder list.

There is an error message in the notification area starting with “No outbox_state entry for messa” but there seems to be no way implemented to see the error message displayed in K9. when I click it, I am navigated to the app but not to an alert section or so

here the error message:

I may be able to just re-create the account and get rid of the behaviour. But disappearing folders are something I wanted to let you know and see if that is something known?