Im curious if the speakon is wired wrong. Maybe you think its in the right spot and it isnt. Those holes are pretty small and the numbers even smaller. Shouldve been resloved by now. Take apart the speakon and post pictures. Pictures of everything helps the most.
I think the key to this output issue is not being able to fully drive the amp. If you can’t light up the clip light your not properly driving the amp with enough voltage. Let’s see what the cleanbox does. We will know soon.
And I’m not suggesting that you don’t need to quadruple check the speakons and post pics.
Just saying that even without a speaker hooked up to the amp, the input signal should be high enough to drive the amp to clipping.