When I join my friends' worlds, the game always spawns my character before it fully loads and I usually die before I can see anything. Today this happened when I left a world while being near a blaze spawner in a Nether Fortress to change my texture pack. I left the world with full health and came back to having 2 health and I was on fire so I died within seconds of being able to see anything and I lost my best sword and my new trident.

Steps to Reproduce

1. Open the Create New World screen
2. Paste the following seed in the seed field: -572946855
3. Enable Starting Map
4. Press Create

Here, the player loses their map before they are allowed to do anything.

Video Example (the necessary segment ends after 10 seconds)

https://youtu.be/4SKTQVOm7qk?t=881