This seems to have been fixed in SOGo 2.3.7.
Not marking events I won't attend
Zimbra is the calendar server.
If there is a recurring event (meeting) and I mark that I won’t be attending one instance of the future meeting on my PC’s thunderbird-lightning client and sync, Zimbra shows it correctly in the web interface (that I won’t be attending).
Afterwards, when I sync to the Android phone using DAVdroid, it does not mark it on the phone as “Attending: No”.
Android: KitKat (4.4.2)
Phone: Nexus 5
I guess this is a problem of the Android calendar provider and/or your calendar app, because it’s their resposibility to fill the data base. DAVdroid just syncs the database with the server.
Can you provide logs and exact instructions on how to reproduce this issue?
Closed because of missing logs.