From the websites
"Despite the advantages it offered, such as smoothness and improved fuel efficiency, the multitronic system experienced malfunctions. The multitronic transmission faced electronic glitches and mechanical issues. Models that feature the six-plate clutch pack that was introduced before or around 2006 were particularly affected.
Symptoms Include
Flashing gear selector (PRNDS indicator) on the dashboard
Hesitation and/or shuddering during acceleration
Inability to select reverse gear
Audi recommends CVT transmission fluid changes at 35,000 and 75,000 miles, however despite this, in some cases transmission failures still occurred even when abiding by the recommended fluid changes"
I would still speak to Milta first.
Check the service history at an Audi dealer. Almost 90,000 miles is way too late for the fluid change - it's really chancing it.
Did you but the car from a dealer. Maybe call the previous owner and ask whether he was aware of the problem.