If an amp is going into protect mode, especially duplicate examples of the amp, then it is likely the electricity coming into the amp where issues lie.
I had a piece of equipment that would go into protection when I turned it on, and it turned out the polarity on my outlets was reversed. Nothing else I owned had ever complained, but the equipment that balked was from a very accomplished manufacturer who designed things to work with proper power. I got the wiring fixed, and everything sounded better.
Some equipment is designed to work with electricity that meets standards for polarity, grounding, voltage, etc. I find the better the equipment the more true that is. It's a good thing to have a proper protection circuit in place when the incoming power could cause damage.