My early 2021 Model X, delivered 12/4/2020, has had the last 3 updates (2020.48.26, 2020.48.35.5, and 2021.4.6) all show completed. However there are features that are "Waiting for update". With 2020.46.26 I called the 800 number shown in the car. They ultimately re-sent the update. The second time I scheduled mobile service and the agent contacted the mainframe folks and they re-sent that update, 2020.48.35.5.
Now the latest update, 2021.4.6, has also choked and puked. As far as I can see it's missing Solitaire game but there could be other issues I don't see. I now have another mobile service scheduled for 3/3/2021. I put in my remarks that I'd like to have the car checked at the local service center. Something tells me it's an MCU or MMU or whatever Tesla calls the main onboard computer that has a bad motherboard or memory or RAM.
It would be nice if Tesla did like Apple with their iOS updates. One of Apple's steps it to verify that the update was indeed downloaded and then installation takes place.