MCX8000 in Serato freezes and looses audio using fx.

I had recently test 2.0 from 003 to 008 updates going back to 1.5 to go out in work field and finding that while using Serato fx the MCX8000 freezes with the Mac for a few seconds when both unfreeze sound goes for less than a second and quicly sound fades to zero, but I can see waveforms are running on Mac and the MCX8000 screens. Had turn volume knobs, fx knobs, pressed play/stop and many other things. But audio comes back only if I turn off and turn on again the MCX8000. Am I us8ng wrong the fx?