Help - There is a problem sending data to the laser

I am having the problem i have seen on these forums but I can’t seem to find the fix. My pc isnt communicating to the laser. i tried uninstalling and re-installing the laser, my comm port is selected, Im getting the message on the console of waiting for connection or port failed to open already in use? i have restarted the pc, the laser and light burn. i had the issue last night and when i re-booted it fixed itself. i was able to engrave but today no avail. i have a big job i need to get done and any assistance would be greatly appreciated. The laser is a desktop monport 40w and im running windows 11.

I don’t understand anything about Windows 11, however, if you can identify which port the CH340 driver appears on, that’s the port you should select in Lightburn.
If you don’t know, try what I would do (it won’t hurt), in Lightburn, check which ports are available and select one at a time. one will probably communicate with the laser machine. If the problem repeats, it will be more difficult to resolve it definitively and it’s not for my knowledge.