If you die while flying an elytra when you respawn you keep the 1 block elytra hitbox. If you go into a 1 block space all you see is inside the block. You can fix this by deploy your elytra again and lading onto the ground.

How to recreate: fly an elytra with fireworks containing a firework star and fly in survival. If you use enough you should get exploded and die(normal behavior).