This is a very odd one.
I'm using an SCS hook to add a component to trains that simply changes the skeletal mesh the skeletal mesh component (M Mesh) on the locomotive to a custom one.
The custom skeletal mesh has the exact same setup as the original (as far as I can tell), other than one additional material, and a slightly modified mesh. It also uses the exact same skeleton as the original (not newly imported, it actually points towards the original skeleton)
Animations and all that work fine, but when a new locomotive is placed, no new freight cars can be coupled, and train derailments (the locomotives just stop dead)
I'm currently under the assumption it's something to do with how the skeletal mesh is used by coupling and derailments in the original locomotive BP, but that's pretty much all I have right now.
The train BP is mostly C++, which I'm not too familiar with, so if someone here knows how the code for trains works, your help would be highly appreciated.