Found an issue with Windows 10 the other day.... It's an issue with serial COM ports over USB....
I can connect to an Arduino board using the IDE, download code to it, and the view my board data using the IDE's serial monitor, and manually type parameters to it too to position my indicators... however, it all falls apart when I'm finished with the IDE and trying to get comms between FGFS and the board using the same COM port. Even after rebooting, just in case the IDE still had ownership of the port, same issue.
I've duckduckgo'd and found other people complaining of this or similar issues on Windows 10 (other applications outside of FGFS). No resolution found so far. The Windows users complaining of the issue had success under other versions of Windows, I've come to W10 from Linux so can't compare to other Windows versions.
I'm only using W10 as it's my work's laptop, becasue my own PC is dead. I never had these issues under Linux. Tried FGFS on my Manjaro VM (W10 host), but it's useless, not enough of a computer.
I know I'm a bit unusual not using off-the-shelf HID compliant devices, but this is a potential show stopper for anyone else wanting to have a go under Windows.
I use Arduino uno boards and the standard IDE that ships for free from Arduino so if I can help let me know something specific to try for you.
I have win 10 PC and laptop, and I also have used it with Ubuntu on the same PC via a USB OS.
All the uno boards I use are cheap clones but any symptom should be the same.
I then use the usb ports for other stuff such as audio mixer desk and guitar pedal banks with no issues.
Fortunately my neighbour is similarly equipped and has more time than me so if I can spark his interest he might be a good resource for you. ( his volvo xc70 now has a few Arduino boards doing various things - quite mad )
Sorry Scott but we're going to drift off your issue now
Before it was ever popular to chip cars, me and a mate used to make little computer boards and have leads hanging out of the bonnet into the car so we could map the ignition and fuel flow ( Golf, merc E190 and SAAB 9000 ) while connected to the parallel port of really early laptops while we drove. We worked in a steelworks on shifts so the night shift was spend racing around the perimeter road trying to get the best power at each 100 revs
Simpler times, more fun...what ever happened to me ??