When I press CTRL+Shift+F12 to display the GSX menu it doesn't appear and a Windows sound plays. I've also tried to show it via the Add-ons GSX menu but still the same result.
P3D v4.3, Windows 10 Pro and additional GSX module running. Restart of Couatl doesn't fix it. No key mapping in P3D is assigned to that combo. I switched to CTRL+Shift+F11 (also free in P3D) but got the same result. Same problem with default aircraft.
Baffled. Would a log help?