Imap IDLE only triggers once per refresh

[Gerrit Jan de Bie]

Hi,

First posting to this list, longtime and happy user of offlineimap.

Till now, I have just run Offlineimap on a schedule, but decided to try IDLE support to get rid of the small delays in delivery of new emails. It only triggers once per refresh.
In the Known Issues you are mentioning that this specific problem should be sent to the mailing list if it occurs.

It does occur in my setup on macOS 10.14, using Offlineimap 7.2.4.

However, in a setup that I made some weeks ago on an rPi 3b+ running Slackware 14.2 (or -current?) and Offlineimap 7.2.3 it did not occur.

In both setups talk to the same remote IMAP server which is a Windows Exchange setup.

What can I do best to help diagnose this issue?

Best regards, Gerrit Jan