I experienced same problem in the actual version of Test Server and in the Real Game, but in my case both of my problems in Island Lake.
Today as guest in an online match i've enter Island Lake from the dam towing other's player chevy with my white western, as soon as i crossed the tunnel the chevy was blocked for me like if there are other player inside (looking at the map appear that i'm inside the chevy and the wws at the same time)
I've had restored the wws to the garage and store it, but chevy was still locked.
The other time that happen to me was playing the actual live version(4.10) with a friend (My friend was host), we were both driving and towing another truck(in total 4 trucks 2 from him and 2 from me) and we cross the tunel( while towing the trucks) from the Dam to Island lake and the towed trucks had locked when they appeared in Island lake (We cross the tunnel in turns and clearing the path for the other).
We try to change to the other locked trucks but his truck and my truck were locked for both.
We try to restore the other trucks to the garage and change to the locked ones in the map but didn't work, so we finish the online session and my friend tryed in the offline, and in offline mode his truck wasn't locked.
I'm sorry but in this case i don't have captures.
Hope it will help.