Like you, we couldn't pinpoint exactly why it was giving us issues, so as a workaround we told FE to open up to This PC rather than Quick Access. It only happened when opening File Explorer in its default location, which is Quick Access by default.
I have seen this exact issue with my users. I believe it was a broken path as such or something with a ridiculously long path-name that caused this trouble. My problem was apparently caused by the Windows-habit of adding 'recently used folders' to that view automatically and you might want to double-check on that feature as well and disable it. You might want to remove everything in there minus 'the usual suspects' like Desktop, Downloads etc. I ran into a problem a while ago where File Explorer was constantly freezing on me because Windows in it's wisdom decided to add something rather indigestible to that list.
Have you checked what's in the Quick Access list of folders ?
