Ok I'm new to mercedes and also new to diesel motors as well but thought this would be the best place to post this issue. So previously to picking up the car I did a couple test drives and the transmission works just as it should. Yesterday I go pick up the car with my F150 and tow dolly and tow the car about 70 miles back to my house. Today when I went to take it for a ride it isn't shifting out of 1st gear. I had the car in neutral when I was towing it and it wasn't making any kind of noises or anything. Not sure what could have happened from there to here but I'm clueless as to what I should be looking for.

Anybody got any tips I can try to figure out why it isn't shifting out of first?