Mods installed:
Tsar's Common Library
Autotsar Motorclub
Autotsar Tuning Atelier - Jaap Wrungler

This issue was reproduceable with only JAAP and Motorclub installed, the moment i hook up a 2M trailer to a JAAP it either glitches out right away or it glitches out when i try to drive away, sometimes launching the car and trailer into the air or the trailer going upside down.

I've encountered this issue in both Solo and on my own server and decided to test it without any other mods installed to make sure it wasn't caused by something else, which sadly was not the case.