[mitch13]

Not sure how long this problem has been going. I have a main library in Calibre but also several other libraries.
Generally I download books to the main library then transfer any books that relate to my other libraries from there. In the past Calibre told me if the ones being transferred were already in the secondary library.
It appears that this is not happening now. Whether it is a bug or some setting in my Calibre I cannot tell.
I would not be surprised if it was a setting in my Calibre!!

mitch13