@Aurum2836C
Do you happen to use
View Manager Pi?
(I don't)
Kovid, I have 1 Library that always opens on a VL.
Is there a preference for to apply a VL on open?

Preferences: Is it possible for you to put some sort of mark on those Preferences that are per-Library (or per-user system)
Currently they are mixed (a relic of when calibre only did 1 Simple Library)