Posted this at Telsa.com too: I had my Model X in for some service and they did a firmware update to 17.28.4cf44833 while there. I got it back and all was good until about the 6th or 7th time I used my keyfob. At that point the keyfob was totally dead. No auto-presenting doors, no buttons work. Car won't start because keyfob isn't in it. I figured the SC left the keyfob too close to the car and the battery died. Used the phone app to get home. Change the battery at home. Checked the voltage on both the new and old battery. Both were good batteries. Keyfob still not working with new battery. We go out to dinner using my wife's keyfob. All is good. Come out of the restaurant and now my wife's keyfob is not working. I'm assuming this had to be something with the firmware update. I've tried rebooting the main screen and removing batteries for an hour or so and replacing them. Nothing seems to work. It's like the car has de-registered them. Anyone else seeing this?