“I’m using a RayMiniS on Windows with LightBurn 2.1.03. Device Manager shows USB-SERIAL CH340 on COM4. LaserGRBL connects and controls the laser normally. In LightBurn, selecting COM4 causes the controller to reset into standby and LightBurn remains on ‘Waiting for connection…’. The device is configured as GRBL. I’ve reinstalled LightBurn and confirmed the CH340 driver is installed
As a start try enabling DTR Signal, maybe it is like the Ray5.