Many EVs do have a 12V. I have a Hyundai Ioniq 6 and they are known to have ICCU failures which cause issues that look exactly like this.
Edit: the cyber truck apparently doesn't have a 12V but rather a 48V system. I'm not sure if this same issue or a similar one is happening, or something else entirely.
This could be an ICCU failure, where the high voltage battery doesn't properly charge the 12V. I have an EV model that is known to have this issue (luckily I haven't had it happen). It can be caused by either hardware or software faults. Still pathetic though lol
Edit: the cyber truck apparently doesn't have a 12V but rather a 48V system. I'm not sure if this same issue or a similar one is happening, or something else entirely.