BR I have the latest Calibre now installed on 3 W10 systems.
2 are Pro, 1 is Home
Calibre installed fine.
OTOH
Windows... those 3 do not look, play or behave the same on my home (not a domain) network, for quite a while (they did, Now I can't see them all from various. A sees B but not C. C sees B B sees A).