Zombie's arm position while holding an item in the offhand is incorrect

Steps to Reproduce:

1. Spawn a zombie;
2. Use the /replaceitem command to put an item (must be an item that a player is able to hold) in its offhand.

Observed Results:
It looks like it's supposed to be holding a bow.

Expected Results:
The arm position doesn't look any different from a regular zombie.

Screenshots/Videos attached: Yes

Notes: Doing this with zombie villagers causes MCPE-50313