Wither spawning and death animations are broken

Spawning Animation:

Observed Results:

1. Only the head spins and the body stands still most of the time, with a few occasional movements;

2. The Wither is completely white during the entire animation;

3. The Wither moves during the spawning animation (MCPE-48265).

Expected Results:

1. The entire Wither spins around while the animation is played;

2. The Wither starts off white, but transitions smoothly into a blue texture and then starts switching back and forth from black to blue until the animation ends;

3. The Wither stays in a single spot until the animation ends.

Death Animation:

Observed Results:

1. The Wither turns white and stays like that during the entire animation.

Expected Results:

1. The Wither turns blue and slowly transitions into a complete white texture before the animation ends.

Notes: The correct animations can be seen in this video at around 6:54 and 7:51, respectively: https://www.youtube.com/watch?v=FQWmBE1W-XE