: If the key box won't accept your code, temporarily disable your device's antivirus or firewall, as these can block the verification script from communicating with the server. Fresh Reinstall
This is the most searched version of the problem. In MSFS, the Honeycomb Bravo Throttle Quadrant has a "Delta" button (the left-most red button) that controls the autopilot disconnect. When it fails, the sim thinks it's constantly being pressed.
(delta check):
v1.1 GPS R-Link 2019