We're still experiencing the same results as well jhoppmann. I've done 3 more trips, all around 7,500-8,500 feet... covers on, no workie. Covers off, works fine. Shore power, works fine.
Took it in again, dealer couldn't replicate the problem at 5,000 feet, even with a low battery. They think it's a voltage issue and wanted me to try to replicate it by taking batteries out of parallel and trying each individually to see if there is a battery problem.
I still think it's a sail switch issue, but dealer is refusing to send it back saying since it works fine, they'll be charged for it.
My video of being able to replicate the problem didn't help apparently. I'm going to escalate up to FR Warranty support directly.
2015 Roo 17
2015 GMC Acadia 3.6L V6