Navio2 power module only works without ESC connected

I have four ESCs connected to a navio2 in a quadcopter X configuration… All but one of the ESCs have no Vcc wire (as per documentation).
I’ve haven’t been able to get the voltage/current monitoring thru the ADC to read properly, and I noticed the one ESC that is wired to provide power to the servo rail was quite hot. I hadn’t flown the copter, was only bench testing and calibrating.
If I disconnected the power module from the ESC wiring harness it powers the navio2 and the Rpi3. However if it’s all fully connected the power module seems to bow out and let the ESC power everything.
Any thoughts?
I’m running arducopter 4.2.0 (updated the emlid image).
This is my first post, any feedback would be appreciated.

Hi Dan,

Can you please share your connection scheme? The power module doesn’t indeed power servo rail. To power it up, you can plug your drone’s BEC into any free channel on the servo rail.