I had to have my Model X towed from my garage on Saturday morning. All screens dead, wouldn’t respond to app, keyfob worked, lights, windows, and doors worked. The car would even charge if plugged in, though it had 230 miles of range so that wasn’t an issue. Called Tesla Roadside, they said the car was reporting no error codes but wouldn’t fully boot. So it got towed. It worked the day before, the only thing that changed was overnight it applied a firmware update. Tech said that it seemed like the binacle display and the MCU couldn’t communicate post update and that somehow kills the power on routine for the car.
In all my years as a Tesla owner I’ve never had a firmware update kill the car like this. I’ve had firmware updates fail but never in a way that left the car undrivable. It wouldn’t shift into drive… I tried.
So, be warned 2021.4.11 may have issue or I may just be unlucky.