2006 Audi A4 CVT transmission troubleshoot

Hello. My CVT transmission leaked oil through one of the cooling hoses.

I took the car to the mechanic, he removed the TCM module and I sent it to repair which some seller from Ebay installed a kit that wont make it shoot the trouble code it is prone to do. My mechanic had replaced one of the pulleys with its bearings. He installed the transmission, and now the car struggles to shift properly. At first it wouldn't shift to reverse. Now it just struggles to shift smoothly as it's supposed to.

My mechanic is saying that it might be TCM since he tried to reset it and it wouldn't respond. I called the Ebay seller and he said it is "IMPOSSIBLE to need additional programming on the TCM since it is the same one from the same car. If the TCM comes from another car, then it needs programming. And it does not affect shifting."

His theory and my mechanic's theory has been bouncing around and I don't know who to believe anymore.

I have a youtube video showing how it sounded before the "repair".
Youtube: Audi B7 CVT 2006 weird transmission sound

I will REALLY appreciate the help on this issue. I can donate more if I get a really good answer. Thanks!