Sculpfun S9 Laser wont turn off

I have bought the Sculpfun S9 laser module for my Acro build and i am having some troubles with getting the laser to work. I am using the MKS tinybee using FluidNC. The laser is powered by a separate power supply to the tinybee board. The laser will turn on and stay on even if only the laser is powered on. I have also found that if the PWM cable touches anything conductive, whether it be a different pin on the board, a metal screw on my desk or my hand it will turn the laser on. Any ideas on how i would go diagnosing this issue?
Thank you in advance

Seems like bad cable or missing grounds. All boards, power supplies need to be grounded together.

Yes, all systems need a common ground. Otherwise the signal cable is floating.

Hi currently experiencing the same issue… may i know if you have it fix already?