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

One of the images shows where the mobs don't burn relative to the powder snow with green concrete and where they burn with red concrete, the other image shows the bug occuring.

Steps to reproduce [by EVGENSYPERPRO]:

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. Summon zombies from different sides.

Steps to reproduce (1.17.20.23 Beta):

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. 
6. 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.

Expected results:
Mobs should not burn just inside the powder snow.

Notes:
This error does not affect players in any way (no freezing effect is observed).

Video:
Minecraft 2021-06-13 17-46-09.mp4