Without fail anytime I traveled via airplane the altimeter on my 910xt would tank. Usually went through the troubleshooting process with them only to finally get a refurb. Happened multiple times.

I've flown with my 935xt before without any issues. For whatever reason I flew earlier this week and sure enough it was showing an elevation of 65k ft afterwards. Having zero expectations of success I recalibrated the altimeter and...voila! It worked!

It's the little things in life.