IOTAVX Sa3 and Pa3 in bridge mono mode/subwoofer

I’ll try and make this quick. I have the iotavx sa3 and pa3 bridged together. Sa3 right speaker. Pa3 left speaker. I recently bought a pair of rels t5i. Connect high level to monoblock per their instructions. 2 issues.... and i didn’t post in subwoofer forum because Rel said this was an issue with the amplifiers. Basically I was hoping there was someone out here has the iotavx stack and has successfully hooked a pair of subwoofers to them. When I turn the amplifiers OFF... the rels get very loud and the woofers vibrate like crazy. Rel says they think it’s a issue with iotavx...and its rare. And it Will probably be unsolvable :(. I’m new to this and don’t know if this can effect the sound when the amps are on...because I need to have the gain and crossover way past where rel says they should at 2 o’clock. I cant really get an answer because rel isn’t very familiar with iotavx and iotavx customer service is practically nonexistent.