The Bug:
Entity names can be seen whilst inside of powder snow/lava.
Steps to Reproduce:
Spawn several entities in a large area of powder snow or lava.
/summon zombified_piglin ~ ~ ~ {Invulnerable:1b,CustomNameVisible:1b,CustomName:"\"TestTestTest\""}→ ❌ Notice how you can see the names of the entities.
Information:
This did not happen in 21w08b.
Can confirm