Core Sync running at maximum although the files are all synced?

Around 2 days ago I noticed my laptop (Mac Pro 2019 Mojave) started sounding like it's about to take off and when I checked the Activity Monitor I notice that Core Sync was taking up 99% CPU although the files are all synced? They all have green checkmarks next to them.

It also did this again with all the files in my CC not having any checkmark or syncing symbol next to them. Both times I went to Uninstall CC and choose reset and it stops. Does anybody know why?