Meeting series disappeared in organizers calender

We have a case open with M$ support.  We were able to do extensive logging and repeat the issue several times for them to have data and a lead to follow.  The Outlook team deemed it an Exchange Online issue.  The Exchange team hasn't responded yet.

Issue:  Organizer creates or modifies a meeting and sends it.  It gets deleted from the organizer's calendar (immediately), or sometimes from the attendee's calendar.

We have ruled out anything we can do with Outlook.  Update, rebuild OST, new Outlook profile, etc.

There is a way to put it back in the Calendar, but nothing to prevent it... SOOOO AGRIVATING!!! 

From MS:

Outlook debug team has analyzed the data collected from Ryan’s PC. Their analysis confirms my initial analysis of the data, we need to understand why the server is throwing this error on frame 922 when “Test13” gets created by Outlook.