Hello Skariks,
Believe it or not, this discovery of yours might be a gift for me. I admit to being very comfortable with my Win 7. It was custom made (not by me exactly) and fits me just right. I've been told that Win 10 isn't much different as compared to 7. But right now is a bad time for me to change my operating system (due to covid).
I was excited about the upgrades to Calibre 5, but my smile soon turned into a poo-poo face when I saw that it was only for Win 10
It's good to know this is working out for you. I will keep you in mind when I give it a try.
CalibreBee