If gamerule "DoMobSpawning" of the world is "false"

And I command "/kill @e", I died.

And I can only see the color of my skull, I can't use my mouse to move.

If I use third person, I can see my name on my character.

But everything are alright, I can use "/tp" and "/summon".

If I kill myself at this situation, I can move my vision now but not my body.

And I can break blocks in this moment.(I can't sit in the minecart but I can move my position in this way)

And I can change my game mode to spectator.(And I can't move)

I can summon a bee and look on its view, but I can't leave its body.