Strange Thrustproblem

Hi guys,

I have a strange problem with my PMDG 737 NGX 600/700/800/900. Sometimes the right OR the left thrust won't work(react) anymore. It appears suddenly and very random. Sometimes just one of the thrusts work during the Cold and Dark, after the take-off, during the approach or i can finish my flight without problems. No bugs with the PMDG T7 so far.Other Aircraft work properly and without any problems. It's only the NGX with the annoying bug. 

I have no idea what to do. I updated FSUIPC and bought a new Joystick (Thrustmaster Hotas X). 

Windows 7 Ultimate x64

FSX incl SP1/2

Some Add-Ons (Airports, Scenery ...)

PMDG T7 / NGX

Active Sky Next

REX4

I use "FSX Borderless" because of a second Monitor and i fly in windowed mode. 

I hope someone can help me.

greetings

Johannes Myer