08 Q7 Trans shudder
 

Hi there all,
I've got a 2008 Q7 4.2 S-Line that just hit the 90k mile realm and up till recently, the car has been a fantastic machine for the family and I. However, just last month I've noticed a shudder in the shifting between 4th and 5th gear, as well as a shudder when downshifting. This issue has made me paranoid so I've taken the car to at least 2 of my trusted local German car shops in town (holding off taking the car to an actual Audi dealership for fear of being taken advantage of) who have found the car to manifest no codes indicating any issue with it. Shortly after the code reading my techs have taken the car for short but rigorous test drives and report no issues. Ironically the car behaves for a little while after having the codes searched, but the shuddering comes back.
I've read other forums that have prescribed the simple fluid flush and have reported positive results. Others have had the valve body replaced to fix the issue. I've mentioned the valve body to my techs, but they've all unanimously concurred that if the valve body were failing (or something of a larger scale) a code surely would've manifested.
I'm just trying to reach out to see if you any of you have had the same issues and if there's possibly another fix to this issue than just a flush, valve body, or (god forbid) a trans replacement.
Thank you in advance!