Steam F40s On Boston Sprinter And Peninsula Corridor Have No Sound On Tsw4

I went to drive the F40 on Peninsula Corridor in TSW4 today and the locomotive had no sound other than the HEP generator. I went in to Boston Sprinter and the F40 there has the same issue. I tried the exact same services in TSW3 and the locomotives sounded as I expected them to. In TSW4 (the app with the issues) all mods were off. In TSW3, where it worked fine, I had several mods on.

I walked around yards and only AI trains had locomotives with engine sounds beyond the HEP generator.

Has anyone else experienced this?

 

Are there certain services in which the engine sound problem occurs or do you maybe have outdated or incompatible (sound) mods that cause sound problems with the F40? I can't reproduce the problem, both F40s sound the same, loud and humming. (PC, Steam)

 

Cab car train #911 from Southampton St. Yard to Boston South. It starts in the cab car but when I get out and run to the back, the engine is silent, both outside and inside. However, for some reason, if I launch F40 train #911 from Boston South to Stoughton, the engine sounds as it should. Now to make it more interesting, if I use the God Mode mod to remove the engine from the Southampton St Yard - Boston train #911 and then spawn in a new F40, it has sound!