Yesterday saw me refine my version 1 throttle changing the Leobodnar joystick card out. It fails all the time due to the poor spring connections on the unit. Probably not an issue if the card is set up and then not disturbed. However, during the 5 years of operation, this card has been disturbed countless times. Now the spring clips fail to hold various wires and the control axis fail to work.
I replaced it for an Arduino Micro Pro. Once all connected, adjusted the code on my desktop computer and checked it was operational. It all worked perfectly. Moved the throttle back into the sim and plugged it in. All the axis were moving by themselves. It proved to be the powered USB Hub causing the issue.
I placed a random capacitor between the ground and the analogue input pin. I have found any value capacitor works from the amazon selection box I purchased. But you must ensure the negative stripe of the electrolytic capacitor is placed on the ground side.
The results for the axis become rock steady!
I hope this helps if you are experiencing this same problem.