I assigned B for my Select Category 7 button (which is blueprints), and Shift+B for my Blueprint Library.
Trying to access library with Shift+B doesn't work. It acts as if only B has been pressed. If I'm in Shape Processing category and press Shift+B the Blueprint category is selected, as if Shift wasn't even registered.
I checked and there are no other overlapping keybinds for B or Shift+B.