Summary:

Despite the fix MCPE-131005, if a undead mob stands right next to a block, it will not burn! Works only if the mob is close to powder snow.

Steps to reproduce:

1. Dig a hole 3 * 3 blocks and 2 blocks high.
2. Place 1 block of powder snow in the center.
3. Place 1 more full block on powder snow.
4.  Add 2 blocks (high) to the corners (to keep the mobs from moving).
5. Summon zombies from different directions and move them close to powder snow.

Observed results:

Undead mobs such as zombies, skeleton etc that are around the north, west and north-west of the powder snow do not burn (this still works in the powder snow corner).

Expected results:

The mobs should burn outside the powder snow.

Video:

Minecraft 2021-07-24 10-26-58 (2).mp4

Image: