2500HD ignition diagnostic help

[2500HD LB7]

Happy 2024 everyone!

This truck due has a intermittent & worsening issue that would cause no crank no start & sometimes would cause the all power to go off when the ignition key's turned.

I just replaced the ignition switch with a Dorman 924-715. Fits fine. But it did not resolve the starting issue or the no power issue. Matter of fact, it now consistantly have no power except the key chimes. 

What am I missing?

Thanks in advance for any/all helps!

Image attached is from prior to this ignition switch work.

[2500HD LB7]

When I turn the key to start, I can hear a click sound & shuts off auxiliary powers (radio, interior lights, OBD, gauge cluster, etc.).