DDJ-RX unresponding after a few seconds

Good evening,

I recently bought a DDJ-RX and I encounter a problem since a few hours. When mixing with rekordbox, after a few minutes the controller does not respond anymore. Apart from the master level, nothing I do on the controller has any effect. When the problem occurs, the meters continue working as expected. The channels that are not on 'PC' mode continue working fine (eq, fx, cue mode etc work properly). 

Quitting rekordbox and opening it again solves the problem, temporarily. 

How can I prevent this from happening again? 

Thanks in advance.

Edit: more info about my config

Mac Pro 2013, Mac OS 10.11

Rekordbox 4.2.5 rev 9056-10456-10385

DDJ-RX: latest update, done yesterday