PRS Machine Z axis Zeroing Issue

[mwn]

Shopbot Enthusiasts,
I have a PRS machine with an ATC on it. I can C3 just fine, switch bits just fine, I can zero each bit without a problem. However, when I want to move from C3 to JH or run a project the Z axis goes up and trips out on overload. What am I missing here? Is there a parameter that I need to change? Thanks for the help. m

[dlcw]

Are you doing a CN73 on all your bits? Are you doing a CN72 to your table surface?

My startup routine is

C3,
Spindle warmup
C1 - grab a bit
CN72

Anytime I change a bit in one of the tool holders I do a CN73 on all my bits (10).

This way I'm assured that all the Z-zero routines are in sync.