I know exactly what's going and and was able to fix it on my end. It has to do with how the hierarchy nodes are named in the shape files. For some reason the trailer's main node was given a WHEELS name instead of MAIN as is standard. OR sees the WHEELS name and thinks they are supposed to be animated, that's what causes the rotation. I went through the shapes individually and manually re-named the hierarchy node in question from WHEELS# to MAIN and the problem was solved on my end.
I considered bringing it up here, but got stuck in a sort of chicken-or-egg dilemma asking myself "Do we adjust the simulator to fit the equipment or do we fix the equipment to suit the simulator?"
Regardless, I've thrown my shapes into a .zip file and attached them here. Feel free to try them out but as always back up your existing files first.