I have 3 users, that I know of, that can not search current mailboxes. They can search current folders and all outlook items but when they search current mailbox they get no results or if the key word is with-in a invitation the invitation will show nothing else. I have re-indexed many times. Even if I log in as myself open my email, which searches fine, and add one of the users to my outlook profile, I still can not get search results to show up. From what I have been told this just started 2 days ago. As for as I can tell there have not been any updates or changes to the system in the pass week.
outlook 2013 or 2016 running on xenapps(6.0) server 2008 R2
Hybrid exchange 2013 office 365 online mode only.
Update: installed outlook 365 on a local computer. In online only same results in cache mode it works unless I hit "more" at the bottom then it everything goes away.