My UFX needs 30 Minutes after startup to pass audio on the outputs. If you crank up the volume its possible to hear the signal very, very silently. After the "waiting time", it jumps to normal level.

    This wouldn't be a major issue if it was 1 - 5 minutes, but a whole live-production standing still for 20 minutes because my interface refuses to pass audio is not acceptable.

I have this problem, all outputs are effected.
It takes 30 minutes for the volume to jump back to expected levels.
I've tried two different mac computers laptop10.12.2 and imac10.11