The bug

When a player in Creative mode enters and leaves lava, the player does not enter and leave the fire state immediately. This is not the case when the player enters and leaves Fire or Soul Fire.

How to reproduce

1. Switch to Creative mode, and then place down Fire, Soul Fire, and lava in an adequate area.
2. Add server-side tick lag using methods such as a performance-expensive data pack for easier reproduction.
3. Enter and leave the lava that has been placed.
   → The player does not enter and leave the fire state immediately.
4. Enter and leave Fire or Soul Fire.
   → The player enters and leaves the same state immediately even with server-side tick lag.