Reply to 2x Kontrol S2 and Traktor Pro 2 issues

Hey guys, me and my mate both own a Kontrol S2 and we are trying to get one to control decks a and b, and the other c and d. The problem here is because they are identical, they seem to clash and one doesn't send midi signals to the computer. I have a feeling the hid controls clash, and it can only pick up one at a time.

We tried generic midi and the in/out ports recognised both of the S2's, but when using the default mode it only shows the one S2.

We are looking for a way to fix this, would anybody be able to help?

Thanks in advance