Sync Centre duplicate.

Question

Hello
I am using windows 10 and my "documents" and "desktop" folder are synced to network drive.
Sometimes sync centre creates duplicate "documents" folder to network drive, but it is empty. Does not contain any files.
After that it starts syncing the new empty "documents" folder. That means I still have access to my files, nothing gets lost, but files are not synced anymore.
I have to copy manually files from old "documents" folder to new and then delete the old one.
There must be a better way to handle this. Why is duplicate folder created and how can I stop this?

All the best