Spawning back at the world spawn after dying by the ender dragon

I spawned back at the world spawn after dying by the ender dragon.

What I expected to happen was...

to spawn next to the bed I had set my spawn point to just before entering the End.

What actually happened was...

I had respawned back to a bed I slept in at an earlier time, then I was respawned again, but at the world spawn. x2

Steps to Reproduce:

1. Sleep in a bed

2. Press on another bed to reset spawn point

3. Enter the End through the End portal

4. Get killed by the ender dragon's 'dragon breath'

I can't seem to replicate this myself in any world other than the particular survival world in which it had first occurred.