Problems with F1 Mapping

Hello there, I try to do myself custom mapping for F1 to control track decks, the overlay deck is not to my needs, so I'm mapping myself, the thing is, I do everything correctly, everything works, but I'm kinda stuck here, I make Volume fader 1 (to MOVE on deck A to left) and Volume fader 2 (to right) works like a charm, but i try to do it for volume faders 3 and 4 (For deck B) they dont work on deck B or any decks what so ever, faders do work because when I try to mapp fader 3 and 4 go left and right it works on deck A like a charm but deck B and other decks dont, what is the problem, Im kinda confused