I recently have encountered a problem when wanting to mix on my DDJ-400.
I hadn't mixed for a month or so, and started up Rekordbox, yet when I played a song from my DDJ-400 the song played for half a second at a much higher speed, and then played a short fragment after 10 seconds of pause. This was on these settings:

This made it impossible to mix, as it seems that Rekordbox freezes for around 10-15 seconds, plays a very short burst of music, then freezes again.
I decided to look at my audio settings, and found out that with the settings below it played as normal, however I didn't hear anything through my headphones, no cued tracks, nor the track playing when listening to the master through my headphones.

The weird thing is that I had none of these problems the last time I mixed, yet now Rekordbox either doesn't play the music, or I'm unable to listen to my cued tracks.
Does anyone know what the issue might be?