PMP 2000 D Losing Volume WHen all Instruments start a song

[mace1530]

Hey folks,
Noob to the this forum, and definitely need some help lol. I upgraded my practice spot mixer to the pmp 2000d a few months ago. There are 3 vocal mics(only 1 using a pedal, me, a tc helicon doubler), a bass with a pod go, an ekit, and a synth/ keys run thru an arturia unit to the mixer. The mixer is plugged into a dedicated 20 amp outlet(nothing else is on this circuit, i ran it new myself). The Synth is plugged into(receptacle) a 15 amp outlet.
The problem is, when the synth or drums come in, it knocks the volume of All the inputs way down, then they gradually raise back up to "operating levels" after 5 to 7 seconds of basically silent volume... What is going on?? lol. In all fairness, im not very familiar with the proper power management of this mixer, so all advice is more than welcome and appreciated!!! Cheers!!!

[MJKlein]

Try turning off all the FX and observe the results.