Settings for the main output reset

Hi all, I have some problems with the Djay Pro software for some days now. After djing for a while (usually after about 5 minutes) the settings for the main output and Pre-cueing are switched from DDJ-RB to the standard setting and the music is played from my Mac. The headphones suddenly lose connection…

What can I do? I use a DDJ RB and standard SONY in-ear headphones. Anyone have a solution for that? Highly appreciated, thanks so much!