Summary:
Breaking a block at the same time as breaking the same lava/water block can spawn lava/water particles instead of the breakable block. Playback methods for survival and creativity are different.

Steps to reproduce (survival):

1. Place lava/water.
2. Give yourself a fatigue effect /effect @s mining_fatigue 1000000 5 true.
3. Take powder snow.
4. Place it in lava/water and immediately start breaking.

Steps to reproduce (creative):

1. Place lava/water.
2. Take powder snow and carpet.
3. Place powder snow in lava and immediately break/Place carpet in water and immediately break.

Observed results:
When the player and lava / water break one block at the same time, water / lava particles appear.

Expected results:
Lava/water particles should not spawn when breaking blocks.

Image:
Survival


Creative