Cross DJ stops doing player cue after few hours playing

I was testing my new setup yesterday and it occurred few times to me to loose the cue functionality on a player, mostly the right player, after few hours of deejaying.
What happens is that when I load a track to that player deck and press the VMS4.1 cue for that deck, no sound is routed to the headphones. But if I try the cue on the other decks it works, just that deck is affected.
This went back to normal after quitting Corss DJ app and opening it again. No reset needed on my American Audio VMS4.1, so I presume that the fault is on the Cross DJ app.
Anyone with the same problem?
Any hints on how to fix it or minor it's impact? I was thinking of going out with Cross DJ for a gig to give it a try, but like this it's impossible.
My setup is:
MacBook Air (13-inch, Mid 2012)
1,8 GHz Intel Core i5
8 GB 1600 MHz DDR3
Intel HD Graphics 4000 1024 MB
256 GB SSD
American Audio VMS4.1 (with MixVibes firmware ver 6)
What happens is that when I load a track to that player deck and press the VMS4.1 cue for that deck, no sound is routed to the headphones. But if I try the cue on the other decks it works, just that deck is affected.
This went back to normal after quitting Corss DJ app and opening it again. No reset needed on my American Audio VMS4.1, so I presume that the fault is on the Cross DJ app.
Anyone with the same problem?
Any hints on how to fix it or minor it's impact? I was thinking of going out with Cross DJ for a gig to give it a try, but like this it's impossible.
My setup is:
MacBook Air (13-inch, Mid 2012)
1,8 GHz Intel Core i5
8 GB 1600 MHz DDR3
Intel HD Graphics 4000 1024 MB
256 GB SSD
American Audio VMS4.1 (with MixVibes firmware ver 6)