when playing in any gamemode in MCPE particles don't update. For example, if you use any block entity, you go into that item's inventory and can place or take out items/blocks from inside. This makes the game stop to detect particle updates that are happening at the time such as rain, snow, lightning, redstone, or potion effect bubbles. Then, upon exiting the entity, the particles suddenly register to hit the ground and all hit at once. This isn't a very big bug, but it can get annoying.