That solved my issue, I had exactly the same situation with AP1 disconnecting and AP2 working fine. It was also a rudder trim binding and after wiggling the joystick, AP1 is working again. Are you also on SU7, maybe that key binding was added there?
Hi! I like the KLM retro livery, but is does have a typo. The name of the aircraft (registration PH-SAD) is 'Evert van Dijk', on the livery it shows as 'Evert van Duk'. There are no very clear pictures of the original aircraft as far as I can find. But the aircraft was named after KLM captain Evert van Dijk.
0571483.jpg (1024×705) Info page Fokker F-27-266 Friendship PH-SAD