Was VW able to resolve your issue? Wanted to share my experience so it may help you. I have a 2018 Tiguan, bought it brand new. Within 5k miles of buying the car, I go to get in it and it's dead! It took many tries, but was finally able to jump it and ride around. Of course, I stopped at a stop sign, the start/stop function kicked in and I was dead in the water. Had to jump it again to get it back to the house and put the battery on a charger. It was fine for a while after that, probably about 6-8 months. Then one day, it happened again! I went to the garage to get in and it was dead, again. This time is was so dead it took days of charging and jumping to get it to start long enough to get it to the dealer, but I got it there. They had to replace the battery, which was covered under warranty, but on the paperwork they charged over $500 back to VW for the repair. They came up with all kinds of outlandish ideas, blah blah blah.

TLDR: It ended up being the KEY! I was leaving the key sitting in the car when not driving it and the car probing for the key was killing the battery. I know, I know. It's absolutely insane that this is able to fly in a car maker the size of VW but after figuring it out, I haven't left the key in it since and lock the car in the garage when I get out---no issues for over a year.