OneDrive folder opening very slowly

Not sure when this started, but when I click on the OneDrive folder on my desktop, or any of the folders inside it (such as Pictures, Documents), the folder opens very slowly. The blue circle goes round for at least 5-10 seconds, then the folder opens. Opening sub-folders is the same.

Any other folder, no problem. Even if I sign out of OD or unlink the PC, the problem still occurs.
OD is working fine, all files are getting backed up and I can see them on my phone.

Edit: Seems to be a File Explorer problem. If I open a folder from Quick Access it opens immediately, if I use Open in new windows or open in new tab it works. If I right-click the file and use Open with... instead of the default Open, it works.

Well this is interesting! See my post here Cross Device Experience host crashes constantly

After uninstalling and re-installing Cross Device, both that and OneDrive folder opening is working correctly again!

How the two can be linked I'll never know. Simply disabling CDEH wasn't enough...