Ender dragons can't destroy end stone but can destroy end stone bricks

This is actually intended and not a bug.

WAI. The only blocks that the ender dragon can't destroy are bedrock, obsidian, end stone, command blocks, and barriers.
See also MC-85537

However, the mechanics of the game may change in new versions. (MC-165218)

Thank you for your report!
However, this issue is Working as Intended.

The report you have submitted is working as intended: MC-85537.

Please note, that mechanics of the game may change between updates.
Things such as graphics, sounds, world creation, biomes, redstone, villagers, and animals may not work the same in current versions.

Full Version History – Snapshot Version History – Feature Requests and Suggestions

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