It is trivially, if not very satisfactorially explained: software bug. Some flag or some register gets set when you are in the tight garage which doesn't get cleared. The fix is to notify Tesla so they can change the code to prevent this. Otherwise you might try pushing the lock button on the fob and then trying to open again to see if that clears this flag or if the new open command will trigger the sensors to look for obstructions again. Or just push the doors manually. That's what I do when they don't open fully.
When I first got my X, the "hold the button" method didn't work due to some problem with my sensors, so it was a long time before I learned how the doors are supposed to work. When you are outside of your garage and they stop low, you only have to hit the open button again to open them fully so long as no obstacle detection is displayed in the MCU. If obstacle detection is displayed in the MCU, you only have to hold the open buttons for them to slowly open until opened fully so long as you don't release the button. There's seldom a need to suffer the embarrassment or potential strain involved in manually lifting them.
Didn't know any of that. Probably plainly stated in the manual.
Not with the fob, probably couldn't open them further with the fob. You would press the open button on the inside of the pillar instead of lifting on the door, alternatively, if you are in the vehicle, you would press the open button on the MCU instead of getting out.
