Pets such as cats and wolves do not teleport to the player before a chunk is unloaded.
This can happen before using commands such as /tp or /home (the latter being from EssentialsX) or when a player is moving quickly via horse or boat. The latter is much more noticeable when exploring new territory and new chunks are being generated and much more of an issue as it can be harder to locate where the pet stopped following you.
Ideally, before a chunk unloads the server should teleport the pets to the player before unloading the chunk (assuming the pet meets the TP requirements of course).
Steps to reproduce:
1. Get pets following you
2. Teleport or move far enough that the pet is now out of chunkloading range
3. The pet may or may not teleport to you.
Thank you for your report!
We're actually already tracking this issue in MC-157494, so I resolved and linked this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
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