Thanks for responding.
Win10 pro - 20H2 19042.868
Yes, I am syncing to OneDrive but only chosen data folders on D Drive - My SSD is partitioned and desktop is on C which is not being copied to OneDrive.
The only thing that has changed recently is the update from 1909 to 20H2 - all OneDrive syncing rules have not been changed. Fences were working perfectly before the update.