A Microsoft file hosting and synchronization service.
This is still happening in Version 23H2 (OS Build 22631.4037)
with OneDrive ver:Build 24.166.0818.0003 (64-bit)
File Explorer version:
File Description: Windows Explorer. File & Product Version: 10.0.22621.4036
In my case it seems to be the same files all the time.
Even if I go clear the recent items folder at %APPDATA%\Microsoft\Windows\Recent[ * | Automatic Destinations\* | Custom Destinations\* ] it still comes back after a bit.
It is very disconcerting.
It does seem to be only OneDrive files that are part of MS365 like .doc, docx, xlsx, etc.