In case anyone is having trouble grounding the Ortur LM2, I came across these handy wall outlet plugs. Just need to connect a wire from the Ortur chassis to a 4mm banana style connector. Just ordered will report back if this rectifies my issues.
real shame nobody make something ‘like’ this but instead it has a 3 prong for the outlet and the tab provides the grounding lug. The the Ortur power supply could be plugged into the adapter and the grounding wire travels up the power supply cable to the laser cutter. I looked and looked but found nothing but lots of THIS type and not the opposite.