Similar thing happened to me just this afternoon.
I clicked 'save' before closing a word file of which the saving destination is online at my OneDrive personal account. After pressing save and then close, unusually, a microsoft malfunction report jumped up and I was pretty shocked because nothing was behaving
abnormal until I clicked save. I reopen the word document and realised the file was restored to a previous version dated 3 days before, in between I had made important changes to the document. I opened the Version History and found the last saved version was
this one that is 3 day old, missing all the changes I made in between.
It was very strange because this morning when I open the file from my OneDrive, all the changes made between now and 3 days ago were saved and present in the document. I had emailed my supervisor just yesterday morning, I thought to check the file attached
with that email I had sent -- it turned out that one was also from the older version! It must have meant that at some point the updates were not syncing properly to the OneDrive. But I couldn't find local recovery files either... missing files.
I have OneDrive personal account and I am a mac user. My autosave option is always on. Does anyone have any clue was went on?