Whenever I try loading cars onto trailers at a certain distance they will fall through the trailer but when I approach them again they start breaking inside of the trailer. Another issue I think is tied to this is that the render distance for vehicles is much lower than usual for me and they will just not render at a certain distance unless the car i'm driving is near the car. If there are mods that cause this I would be eternally grateful to know any possible fixes.
You might have a certain mod installed. Luuk’s performance booster mod can make cars fall through trailers because any collisions more than 15 feet away will be rendered but any less and it won’t be rendered, so it goes right through.