Hello ... Same problem, uncontrolled throttle. I have tried everything and several, in all it does the same and only only with the CRJ. Seeing as it is a common bug, I wait for an update.
It is clear that MFS does not have, at the moment, a solved LNAV system. Since it was released, we have the same problem and there is no solution. Aerosoft CRJ was my hope but they have not succeeded either. Another $ 50 that I have given away.