Wither Boss projectile miss-targeting when in water stream.

I accidentally found the problem that wither the boss shoots his head on the target as "when he is drunk", when he is in the water.

Steps to reproduce:

1. Make a cage for a wither (like in the video I sent) and cage him
2. Make a target (preferably straight in the direction) Then let the wither shoot in the "dry" cage. (He will shoot straight)
3. Put the water next to him and watch him shoot off target (Like in the attachment)

Observed Results:
Wither in the water shooting off his target

Expected Results:
Water at the tail of the wither should not affect the trajectory of the wither heads

I have attached the world where this error happened here: https://www.uschovna.cz/zasilka/QAIM4R4AJ9J7N9NL-FY7/
Thanks, krampi