I had this on the very first flight.
I use FSUIPC 7 for axis assignments and Calibration, so I guess something has been out of sync on my system.
I have tried to replicate, but all seems fine now.
Sorry for any inconvenience.
Otherwise it´s great to be back in a Twin Otter again - nice job
Are there any alternatives to using the mixture axis? I'm using the Thrustmaster TCA and don't have an axis to spare. It tried assigning buttons to SET MIXTURE 1 RICH and SET MIXTURE LEAN 1, but that doesn't seem to work. I'm a bit surprised that the FUEL VALVE inputs aren't used instead since it just seems to be an on/off input.