A Microsoft file hosting and synchronization service.
Same problem for me.
It took me a while to isolate the root cause of these never ending and frequent reboots to finally identify OneDrive as the single reason.
It is really annoying as it happens when on Teams or editing .DOC or .XLS or working in general. A powerful Mac Studio M1 Ultra and it can barely cope with the CPU overload requested by OneDrive processes. It is a shame. What can we do to solve it? Just do not use OneDrive even if we paid for it?