In the changelog it says
Mining speed and blast resistance of creaking hearts is doubled
However, creaking hearts take longer time to mine in snapshot than in 1.21.3.
Steps to reproduce:
Create a world in 1.21.3 and place down 4 creaking hearts.
Give yourself 2 netherite axe with Efficiency 18 and 17 respectively.
Run /tick rate 1.
Mine a creaking heart with these axes. Both axes should mine instantly.
Open the world in 24w46a. Run /tick rate 1.
Mine the rest creaking hearts.
(x)Note you cannot mine instantly with Efficiency 17 one, but Efficiency 18 is fine.
Comments 2
Thank you for your report!
After consideration, the issue is being closed as Working as Intended.
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 – The official Minecraft feedback site
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support (Technical Issues) – 📧 Microsoft Support (Account Issues)
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki
This rather seems like a mistake on the changelog than a mistake in the change itself.