[Users] CM locked up, but no network operations ongoing

[Marco Moock]

Hello!

I am using CM 4.3.0 on Slackware.
After some time, CM is locked up, I cannot select other messages or
folders, but I can compose new messages.

In the net log, I see that IMAP NOOP is being used.

[2024-10-17 12:17:00] IMAP> 335 NOOP 
[2024-10-17 12:17:00] IMAP< 335 OK Completed 

File -> Exit or sync folders is also greyed out.

What can cause that?

I operate my own IMAP server with Cyrus, if needed I can check the logs
there too.

-- 
kind regards
Marco