I believe the Cybertruck …
I believe the Cybertruck (and a lot of other EV's) use a heat pump system for heating instead of resistive heaters as they are much more efficient. A heat pump is simply a reversible A/C unit. Unfortunately, as owners of home heat pumps in cold climates know well, heat pumps stop working at extremely cold temperatures. That's likely what happened here, I'm guessing the Cybertruck doesn't have a backup resistive heater.