The pose of a mannequin is reset when it starts riding an entity or the world is reloaded while it's riding an entity

When a mannequin rides an entity, its pose nbt is reset to standing. Using the data modify command can then be used to change the pose to anything else, which actually updates the pose. Some poses seem to work fine, while others like crouching and sleeping turn into a combination of that and the sitting pose. Upon unloading and reloading (such as quitting and rejoining the world), the nbt is then reset back to standing.

Expected behavior would be either:

• The pose nbt is not reset to standing when mounting a mannequin on an entity or when reloading it

• The pose nbt should always remain standing while a mannequin is on an entity, and should be instantly fixed after using data modify instead of requiring a reload to be fixed.

It should also be noted that in a summon command where a mannequin is a passenger, the pose nbt is always set to standing, the same way the pose is reset to standing when using /ride to make the mannequin mount an entity.