I’ve had this basically since the launch of the game, but as it stands: When I hit my bound button to decrease the Prop RPM, seemingly at random the right hand RPM knob gets reduced varyingly moreso than the left. If not corrected, it causes really quite the discrepancy.
I do not know as of yet if it still happens when it’s bound to a keyboard button, but bound to my joystick it certainly does this.
Been a problem foe some time. You can bind the left and right prop actions to the same button to solve this problem. While this solution works for twin engine aircraft, the double binding causes a CTD when flying a single engine aircraft.
I just tested it and you’re right: Increase Propeller Pitch still works when it’s bound to all 4, but Decrease crashes the game.
It doesn’t really solve the problem. If you keep the button pushed, (or on my case the rotary selector) both engine RPMs e.g. are decreasing at the same rate.
If you decrease the RPM in small steps, the right engine RPM decreases noticeable faster than the left engine RPM.