Beam target of ender crystals on obsidian pillars does not update when ender dragon spawn sequence is stopped

When you stop the ender dragon respawn sequence while some of the ender crystals have a beam pointing to the center, the beam stays instead of being removed.

How to reproduce

1. Kill the ender dragon

2. Start the respawning sequence

3. Wait until at least one of the ender crystals on top of a obsidian pillar has a beam pointing to the center

4. Destroy the ender crystals at the portal to stop the sequence

The ender crystal on the obsidian pillar has still a beam pointing to the center