Problem with interface Scarlett 2i2 + rekordbox

Hi guys. The problem is:

When I change my audio output from Core Audio to my audio interface (Scarlett 2i2) all of my tracks seem to play in fast forward even though the BPM counter seems fine. It doesn't matter what sample rate I set it to or other preferences I change. Wtf is going on? I cant seem to find any answers online.

iMac with Sierra