I think this could be solvable, but with some effort.
Go through ALL your electronics and make sure everything has a common 0 V reference point. That includes the FRAME of the machine. Hard-wire all that to the Neutral ONLY.
Then connect the Neutral to the Earth via a 10 ohm power resistor. That should stop the leakage going to Earth, and send it all to neutral.
The problem is that this may, or may not, violate the machine grounding rules where you live.
Underlying all this is the real problem, that the electrical grounding rules and the design of the earth leakage breakers, were all designed before the advent of switch-mode power supplies and power electronics on machinery. They are, to a significant degree, simply incompatible.
An alternative is that you comply with the grounding rules as far as the frame goes, but you float your entire electronics system, using a Neutral bolt as the 'safety ground'. Got a large heat sink panel? Float it. Got screening on your power cables? Float all screening. Got an earth wire going to a large motor? Make sure the windings are floating wrt the motor frame. Then, finally, you rely on the Neutral/Earth linkage back at your main switchboard.
But the simplest solution is to remove ALL earth leakage breakers from your CNC machinery. A bit of a scary thought in some ways at first - but remember that the machines will still be fully earthed, per regs.
My 2c
Cheers
Roger