Let the fun begin !!! ???

[JAZZCNC]

I need a re-cap on what your using for the main PSU.! . . . Safety relay won't do anything for inrush current if your using toroidal PSU.
If PSU is toroidal then try a D rated MCB.!! . . . . But first you need check everything else is wired correct because the relay and switch shouldn't make any difference so if removing made a difference then suggests you got something wrong.?

Also Not sure what your meaning by using an Input for E-stop.?. . . If your meaning to ONLY use an input for the e-stop then it's a Bad idea.!! All you will be doing is relying on the Software to stop the machine which isn't safe at all.
The correct way is to remove power using relays and then inform Control software the E-stop as happened via an input. Only thing the Input is used for is telling software to stop the G-code and don't allow Control to reset until input state changes.