The bug

When a creaking spawns from a creaking heart, it will persist after world reload. However, subsequent respawned creakings from the same heart won't persist after world reload.

Original (outdated) description

According to the 24w46a changelog:

Creakings will now persist when a world is reloaded.

However this is not the case and creakings spawned from a creaking heart will not persist when the world is reloaded unless it has been hit once.

How to reproduce

1. Spawn a creaking with a creaking heart placed between 2 pale oak logs.
2. Wait for the creaking to spawn and execute this command: /effect give @n[type=creaking] glowing infinite
3. Reload the world.

Expected result
After world reload, the creaking with glowing would have persisted.

Observed result
The creaking with glowing despawned, and another one has spawned.