It is absolutely amazing how many issues are solved with a reboot and how often that fact is forgotten.
So you say, don't bother with #1 and #2 yet, you are not 90º or more sure 1 or 2 would solve this?
I think you misunderstood what I wrote. Personally I would have tried first one and then the other but then your problem was solved with a simple reboot, so my suggestions were overkill. Now I am wondering if quitting and rest restarting Finder might have been enough?