Spindle starts suddenly without my command!

Happened twice in 2 weeks. My spindle starts suddenly without my command. I was sitting and playing with my phone and suddely i see that spindle starts to turn. I use chineese mach3 ethernet controller. I know there is no trust on chineese controllers but this is my 3rd controller from this brand. the other two work fine. My spindle is HERTZ 2.2kw trukish brand which is fine. VFD is again chineese brand called LiteOn EVO6000 1 to 3 phase. Controller commands vfd through PWM.

Maybe you just got lucky with the first two?

If Mach3 is not starting the spindle, then it's the controller.