Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
Performing a item search in the O365 Admin Search & Investigation, the system reports 260,000(ish) unindexed items.
Is there a way - as I continue to search - to force it to re-index those items without contacting MS support.
By this article, some of the unindexed files could be file attachments...
https://support.office.com/en-us/article/Unindexed-items-in-Content-Search-in-Office-365-d1691de4-ca0d-446f-a0d0-373a4fc8487b?wt.mc_id=o365_portal_mmaven&ui=en-US&rs=en-US&ad=US