Spectating Hardcore World breaks Chunkloading

To trigger:

• Create a world in hardcore mode
• Die
• Choose "Spectate World"
• You will respawn, but the internal server doesn't load chunks (gets stuck at "waiting for chunk")

To fix:

• Open the world to lan with cheats enabled
• Put yourself in creative mode (/gamemode creative)
• Exit and Re-enter the world
• The chunks are now loading again.