Desktop client not working & high CPU

i’ve been experiencing this issue for a while but cannot find a solution to it, where i use my own server and use it to sync 4 devices.
These are 1x Linux and 3x Windows10 devices. All work perfectly apart from one of the windows 10 devices.

This problematic client has had the client uninstalled, manually remove all (that i can find) traces; registry with ‘nextcloud’ keywork search, c:\programfiles, and the sync folder itself have all been deleted. Reinstall the latest client and it will be fine for a while.

But then it will randomly stop syncing. System tray icon will be grey and unable to right click it. Taskmanager shows 100% of a core on the nextcloud.exe process and it doesnt correct itself after a number of hours.
Going to the nextcloud URL in a browser works so there doesn’t appear to be any network type issues.

i was hoping that running ‘nextcloud.exe --logfile nextcloud.log’ would generate something, but no… the file isnt even created so i’ve no logs to look at or provide you.

i’m wondering if this might have something to do with updates. appears i’m running 3.3.3, and i see 3.3.4 is latest current. Problem is that i’ve had this issue for a number of releases (certainly the last 2-3).

what could be the issue?