Audi TT jumps after engine change

Hi, im new to the forum. I have a 1999 Audi TT. around a year back something went wrong with the engine and it was replaced by the garage with a brand new engine. Ever since that date when the car gets hot and i am at high speed and a rev the car a bit more, it jerks/jumps a little does anybody know what might cause this?

tHANKS

engine mounts or trans mount broken.