The bug

Experience orbs are no longer affected by the fog from powder snow/lava.

How to reproduce

• Throw some Bottles of Enchanting inside a large area of powder snow/lava
  →  Notice how you can clearly see the experiences orbs

Note: This is quite difficult to reproduce with lava as the experience orbs are almost instantly burned and destroyed, but it can still be seen for a split second. This did not happen in 21w08b.