I'm switching from basic authentication to Modern Authentication in my Znuny (6.4.5) setup.
Sending/receiving mails works fine.
But every few days, I get the notification that The token has expired.
All I have to do at that point, is click on the notification, press, "request new token", and all is good.
But, I'm planning a vacation sooner or later

Other systems I'm using seem to be able to refresh the token, themselves, so I suspect it is also supposed to work that way in Znuny.
Any suggestions how to debug?