[MerlinMama]

Since I want certain libraries at the top of my list, I had the tweak set to sort the libraries alphabetically when there's more than one. I then added a letter at the beginning in the order I wanted them. The images show the tweak setting, the libraries in Quick Switch, and the libraries in Copy-to-Library. As you can see, it puts B at the end, after Z. The other Copy-to-Library screen has a check box to sort alphabetically, so that one is fine.

Is this because my B Library is in a different location? I don't think that should matter, but it's the only thing I can think of.

I also have restarted Calibre since adding my new library and deleting the other libraries (E through J).