A Microsoft file hosting and synchronization service.
They do not give a damn. Onedrive on Mac has had issues for months with hardly any response for MS. Save yourself even more wasted time and move to Google drive or Dropbox. I am moving all my files to Google drive and it syncs fast with no issues, no freezing, no hours of mysterious "processing changes", no silent one drive client crashes, no freezing of finder when looking for files, no random 10minute waits to sync kB sized files, no system reboots. You don't realise how trylly garbage onedrive is until you use a system that actually works. Also google drive is Apple silicon native and use the new file system rules and it has no issues. It seems the problem is with the serious incompetence of Microsoft engineers not with anything Apple is doing. Rood riddence to this absolute abomination of code