The MCB didnt smoke, it was the contactor- A1-A2 coil.
The tricky thing is sometimes the VFD will start fine, to the point it will communicate with linuxCNC start the spindle over serial etc and sometimes the breaker trips but it always trips at the same point, not at power up but a few seconds in, when the click of the internal relay happens (I assume it's a relay making this sound). I', thinking if the wiring was faulty it would present this issue everytime, but that isn't the case. I added the EMI filter, it's not part of the VFD.