Calendar events being deleted after adding attachments

Question

Our application creates calendar events in Outlook on behalf of our users via the graph api. For one of our customers, their events are being deleted intermittently after adding attachments.

When creating an event, our application creates the calendar event, then adds attachments if there are any, and finally adds attendees all as separate api requests. The reason for this is that attachments aren’t visible to attendees unless the attendees are added after the attachment is already on the event.

Some of the time, an event that our app creates is deleted within a few fractions of a second if the user included an attachment. Because the issue stopped happening when we asked our customer to stop using attachments for a few weeks we are confident that attachments are the issue. Once they started creating events with attachments via our app again, the issue began happening again.

This is a major blocker for our enterprise customers, and we would like to know what the next step is in allowing our customers to create events with attachments.