I have an 03 Audi tt FWD that will usually run fine until it is warmed up. When it is warm it sometimes won't shift or will try and then jam hard into the next gear. I got the fluid flushed and changed but still the same problem. Today I drove the car and it was doing it after It warmed up then I was on the freeway cruising for 20 mins and when I got off it wasn't doing it at first again. Could there be a filter that is getting plugged or something sticking? Should I try some trans tune?

When I brought it in to get the fluid changed he said there wasn't any codes to pull for the transmission.

 

I had a similar, but not as severe, problem in my 2005 auto FWD. If it is the same issue, it's an electronic problem, not mechanical. Mine turned out to be problems with the Valve Body/valve body solenoids. Dealer said, "we never have problems with these." LOL. Fortunately for me it was still covered by warranty as it is an expensive fix.
Good luck.