OneNote Files Disappeared

I have been using OneNote - there were files in a notebook and a few files in the sticky notes. I may be wrong but I think there were two notebooks - I thought it odd but never really investigated that. 

I noticed the Android notification page had an entry for OneNote that said "working on it..."

The notification never changed so I decided to investigate. I signed out of OneNote, then back in. The sticky notes are there - but the bulk of the files that were in the notebook are gone. There is one notebook but it's empty. 

I have tried a variety of ways to look for the files in OneNote in Windows, but nothing. I'm not even sure if it ever synced to Windows since I only have used it in Android. 

I can't any sort of log in Android, and searching the files on the Android device turned up nothing. 

I'm stuck! Any help to get those files back would be greatly appreciated.