Here is the sequence of events:
1 - Boot into Windows 10
2 - Start FSX Steam Edition Free Flight. Microsoft Sidewinder 2 Force Feedback USB-connected joystick is working OK.
3 - End flight. Close FSX.
4 - Start AFS2. Fly. Joystick is working OK.
5 - Close AFS2.
6 - Start FSX Free Flight. Joystick no worky. In Controls Settings it says "Your Joystick has been disconnected".
7 - Rinse and repeat. I have to reboot the PC in order to re-connect the joystick to FSX!
Has anybody else seen this behaviour? Is it a known bug?