I've been experiencing persistent File Explorer freezes when operating in Dropbox folders under Windows 10. I have begun to wonder if Dropbox is somehow involved, as there do not seem to be any similar errors occuring to other people for Windows alone. My wife's computer has been experiencing a similar problem; we share a Dropbox account.
It could be any action - moving or renaming. Haven't seen it with Dropbox off. I followed your suggestion, then got busy and lost track. Another odd thing- Dropbox doesn't start with Windows like it's set to, at least not all the time. Maybe reinstallation would help that. My wife's computer's File Explorer has been flaking out regularly in the same way. I have not been able to get her to shut down Dropbox to see what happens.