Glad you got it sorted. I was fairly confident it was Windows but as you had the two ports showing I did not want to make you spend money and it was something else.
There really is some messy behaviour with Win7 on the new cubes and that’s why it’s not officially supported.
Why use windows 7 isn’t this now Redundant
I messed around with this for a while and just put W10 upgrade on. Funny thing was once it finds port it asks you to unplug, hit OK, and plug back in. It never finds it again. It reverts the port to Bootloader. So I just hit OK and all went perfect.