Channel volume on qu24 is turned down (not off) and input is still heard in the house mix, but source drops out of ME-1 input completely. Turn volume back up on channel in QU and then returns to ME-1?
Ok, so what are you wanting to happen. Sounds like your ME-1 output config is set at post fader(or at least follow fader). Do the signals also drop out when you mute the channel?