Any activation of third-party resource packs makes the textures & models of rabbits turn into legacy ones

If you activate any third-party resource packs (even including some from Marketplace), the textures and models of rabbits turn into old ones. Even if the pack does not make any possible changes to the rabbit textures or models.

For example, I have made a pure panorama-changing pack (I only changed the pictures of panoramas), and I have changed nothing regarding the vanilla models or textures. When I enter the game, I Immediately found that the textures and models of rabbits turned into legacy appearances.