Was not tested in an isolated environment, and is not 100% consistently reproducible, yet occurs often enough (and to some players on a server the issue is persistent).
Examples include:

• (Very common) Using a lead on a Mo' Creatures mob can appear to work on the client, but not actually work on the server (and the animal indeed is not pulled)
• Interacting with tamed Bunnies by right clicking on them is supposed to place them on the player's head. This can not work visually on the client, which looks like nothing is happening, but once the player moves and crouches again the bunny gets off their head and reappears next to them.

Reproduced in an isolated environment (dedicated server).

• Lead does not work on a tamed pet:
  
  
  
  Also creates desync issues in the player's inventory.

• While being non-opped, the client will still visually show you can pick up another player's Bunny, but when crouching the Bunny will teleport back to where it was.
  

• Sometimes, the player will try to interact with a Bunny to carry them on their head, and it will not look like it's working to the client.
  
  Yet it is a desync issue, and to another player on the server it does show:
  

Excuse me, sorry if this is annoying but are there any news around this issue? I saw in my game that something weird happened with my Manticore pet and this is all i could find. Thank you and sorry for any inconvenience.