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

steve 1 Reputation point
2021-11-09T15:13:49.943+00:00

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

Microsoft Graph Extensions API
Microsoft Graph Extensions API
A Microsoft API that allows you to extend the graph API resources to save the data of your own application.
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Microsoft Graph Calendar API
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