I went through a similar issue a while back and managed to sort it out by running all my program as administrator. I can’t explain why and how but this was the fix.
As for the problem itself, usually you get such issues on W10 when there is already a software using the port in the background.
Maybe you already tried this, but try to remove completely the Port 4 driver and then reboot the computer. While doing so unplug any cables connected to the port until the computer is up and running again. Then replug the cable to allow windows to lock for the driver. Let’s give it a try !
But once again, running program as administrator solved my issues.