I did not go through anything like the problems that some others have had. I just gave the dealer my written comments that I quoted above and told the service rep I would be available to take a test drive. The service technician did not need me to do that.
Here is the write up from the technician:
"Test drove car-When vehicle is in 5th gear customer's issue is observed (regardless of manual/sport setting. Issue occurs in 5th). Check fault memory. No relevant faults logged. Check trans fluid level/condition. Fluid slightly grey. But not excessively dark or contaminated. Check vehicle E. software status and contact ZF transmission rep. As per transmission rep, mechatroics/valve body is faulty and requires replacement along with use of new trans oil"
I don't know why there were no faults logged. It's odd how the car will record somethings and not others.
I do have to say that I would rather have had the solution be a software reprogram than this hardware issue since it would have been a lot cheaper but the hardware change does seem to have solved the problem for me.