[horde] Horde and ActiveSync on Android ?

[john]

Hi,
We have another issue with syncing Android to the Horde.  The server is a
CentOS 6.9 Final, kernel 2.6.32-642.6.2.el6.x86_64.

We have the Horde (v. 5.2.22) and ActiveSync (v. 2.39.2), and calendar sync
works flawlessly with an iPhone 7+.  Any events I add on the web GUI are
immediately present on the iPhone (and vice versa), and any deletions -
ditto.  

My wife was having issues with a Samsung S7.  She was using my account and
password, and just selected 'calendar' rather than tasks and e-mails.
There were no events being synced.   If she deleted the acount and
recreated it, then all the events present in the Horde calendar appeared
in the calendar on her telephone, but any subsequent edits to the calendar,
did not reflect on the telephone. 

She received her new S9 yesterday, and it's the same story.  She adds the
account, and all of the events appear.  I then add another event, and it
doesn't appear on her telephone.  

If she deletes or edits one of the events that she can see, it's synced to
the Horde GUI.  In short, it seems that any modifications made outside her
mobile device are not reflected on that device unless the account is
removed and re-added. 

Are there known issues with Android and ActiveSync?   Strangely, other
ActiveSync accounts she has on her phone (her work account for example) are
synching perfectly.

I can post the active.log but it's huge.  What am I looking for in it? 

Many thanks.