Extension data in events in a shared calendar periodically being wiped, by SharingSyncAssistant?

steve 1

We are creating events in Outlook shared calendars using the Graph API, then adding data via openTypeExtension.

We have seen the extension data being wiped periodically (~every 3hrs), and it looks like the outlook "SharingSyncAssistant" service is responsible for this, having cross-referenced the times this happens against its logs.

In my local reproduction, I am the "sharee" of the calendar, not the owner, but the events and extension data are uploaded via my account.

This causes significant problems as we rely on this data to avoid re-uploading events. Is this a bug or any idea how to workaround or configure to avoid the problem?

Many thanks

P.S. I have tried adding data via singleValueExtendedProperties, this is also treated in the same way

steve 1 Reputation point

2021-11-15T11:49:32.13+00:00

The problem is that when adding openTypeExtension (or singleValueExtendedProperties) data, it is only created in the sharee's local copy of the calendar. I have inspected this with MFCMAPI and the extension data does not make it to the owner calendar. So when the sharing sync assistant runs every 3 hours, it thinks the extension data should not be there and syncs this over to the sharee copy. Could someone from Microsoft confirm this is a bug with msgraph and/or the syncing mechanism? Is there anywhere else I can report bugs directly to Microsoft?