My files are kept in the Documents folder and easily accessible. When I first opened up Recent (when this happened), I noticed that the list was 'empty', but that there were a few displayed under OneDrive, which I don't remember ever seeing prior to this. Therefore, it appears that my history of files opened from months, years is gone and it is only listing those that With the list empty, I can open a file in any of the products and that file is now listed in the Recent list. I noticed this after I had rebooted my MAC and had been previously Previously, there were many many items in the lists for both Word, Excel, and PowerPoint.
I recently noticed that my Recent items for Word, Excel, and PowerPoint are not displaying any items.