Summary:

The mob disappears in powder snow from the player when the player is above the mob (seen when jumping).

This is possibly related to MCPE-121402.

Steps to reproduce:

1. Place powder snow three blocks high and two blocks long.
2. Summon the mob in powder snow.
3. Stand next to him (in powder snow) and start jumping.

Observed results:

The mob disappears when jumping.

Expected results:

The mob shouldn't disappear like that.

Video:

2021-03-16 14-03-46.mp4