Duplicate calendar entries when created by outlook invitation

Hello, not sure if it is a KOE issue or rather a core issue - when creating an invitation for a resource from outlook I observer that later in the webapp there are two visible entries, one with the correct start and end times and one additional entry with the same title but without start and end times. Is that a sync issue of some sort?

can you exlpain a bit more which versions you are using (koe, core, z-push and webapp), on which client you initially create the appointment, where you accept the meeting, etc.

We use kopano core 8.2.1, webapp, z-push 2.3.6 KOE is 1.4 for some users and 1.3.156 for the others.
But it seems that my recent upgrade of the webapp to 3.3.1 fixed the issue, all the entries that we had have now vanished. So I suppose it was some sort of misinterpretation by the webapp.

yes, there was a related fix in WebApp https://jira.kopano.io/browse/KW-1347