Placing an end crystal when entering The End prevents Ender Dragon from spawning

The bug

When entering The End for the first time, immediately placing an end crystal on the obsidian platform will prevent the ender dragon from spawning, and also generate the exit portal, skipping the need for the dragon fight altogether.

How to reproduce

1. Obtain an end crystal
2. Enter an active overworld end portal
3. Place the end crystal as soon as you enter the end dimension

Observed results

The ender dragon will not appear, and the exit portal will be generated already.

Expected results

Placing an end crystal shouldn't prevent the dragon from spawning, and the exit portal should only be generated/activated when the dragon is defeated.

Code analysis

Code analysis by [Mod] Chandler can be found in this comment.