A Microsoft file hosting and synchronization service.
It's now mid June 2025, and I got this (and other) issues with OneDrive since a few weeks ago!
Another weird issue is that the text "Windows" (!) doesn't seems to be allowed in most (but not all) catalogs and/or filenames when backing up to OneDrive!
(I read somewhere that this is a known issue...)
Microsoft, wake up and fix this NOW!!!