Got the Tesla update a few days back, and got 6.8.0 on the way home today. I was so excited, I manually started the update, and checked on the truck after about 20 minutes. Now, if that adapter would show up, I'd be set!
Similar here.
Unfortunately 6.8 has been ready to install for 3 nights and it still hasn't installed. I tried hitting install now, no joy. Threw a charger on my 12v battery tonight to see if that does the trick.