Mobs are not tracking or trampling turtle eggs

Hello,
Apologies if this is the wrong place to post this question.

Players on my server are having a problem where Zombie Pigmen are not attempting to trample turtle eggs, a necessary part of our gold farm design. I tested it myself in creative mode on flat ground with each type of undead mob, and confirmed they are not trying to attack the egg. Very frustrating and strange behavior! I want the players to be happy, so I began debugging:

Here’s everything I have tried so far, but to no avail:

  1. Gamerule mobGriefing is (and always has been) set to true.
  2. Google searches for the issue usually result in a forum post suggesting it is related to a gamerule or a plugin, which is not the case.
  3. Removed all plugins, (WorldEdit and AutoBackup) requiring a reboot of the server.
  4. I have scoured the configs of paper.yml, bukkit.yml, and spigot.yml for anything related to mobs. Each option is either left at default or matches vanilla.

The server is running Paper v157 1.14.4, although the issue has persisted since v152. The server has been running flawlessly otherwise with no lag. Any help with this is appreciated.

Thank you!

Edit: Learned something new! Apparently the vanilla gamerules are per-world. mobGriefing was set to false in the NBT data for the Nether.