Serial Port crashes

I just got my Ortur master 2 and the usb port crashes if I move the laser to fast (push the move button) I have to disconnect and reconnect ( LaserGRBL works with no issues ) I think it is a buffer overflow Problem. Two different Laptops and both do it.

Can you confirm please if you are running in mm/min or mm/sec in lightburn
Edit menu -> Settings “Scale” better for diode mm/min?

I’ve made some changes to how this code handles the command sending to the controller.