With complex management on i seem to be handling the 109 engine with care and treating it like a baby making sure that i dont throttle to fast and no drastic changes in mixture and prop. After receiving a rating to fly an aircraft in real like with a CSU and multiple pitch prop i thought i could handle it

(haha shows what i know) but after an average 5 mins of dogfighting the engines levers do not respond to my joystick input and they all freeze in their place. Any reason why this occurs? Is this a bug? Or some little quirk that i am not aware of in the 109?