So I have had the S8 in for some small corrosion repairs and one panel that got resprayed is where the fuel filler door is.
I did most of the disassembly and assembly myself, but one of the workers of the shop did the fuel filler door.
Now guess where I have an issue.
The problem is that when I press the fuel filler door release button, it definitely actuates the lock, but the door doesn't 'pop' open. The door and the lock move smoothly.
Since the mechanism is so simple, I suspect that there must have been a spring somewhere that I have previously never noticed when it was still working properly because I wasn't looking for one.
I did a thorough inspection and I think there is just one location where maybe a flat leaf-spring could have lived; right inside the locking part (item 5), pushing against the 'thing that the lock slides into which is attached to the door'
https://audi.7zap.com/de/rdw/audi+a8.../8/809-809090/
Could someone confirm? I now have to stick a bank card between the car and fuel filler door to pre-load the door, then walk back to the passenger door to press the fuel filler door release button which is highly annoying and not good for my new paint.