Mooshroom back mushrooms are not aligned properly with the mooshroom model. They float about half a pixel above the back. The head mushroom is not affected by this issue.
The attached screenshot mooshroom_floating_mushrooms.png demonstrates this.
Expected Result
Mooshroom back mushrooms are connected to the body.
Observed Result
Mooshroom back mushrooms float above the body.
Closing as a duplicate of MCPE-53449.