to make a long story short eventually I had to replace the whole transmission by another shop. I had a feeling the shop I brought my Cayenne to in first place messed up my transmission but could not do anything. the guy closed the shop and disappeared.

ALX5

 

i had similar issues with thumping into and out of 3rd, maybe a little in 5th too.

Diagnosed as valve body. Just had that replaced included full oil, filter service etc and reprogram of TCM - total cost with VAT....£1734.

Now shifts nicely....