When placing splash potions in creative into a cauldron, the same type of potion is supposed to add on to the amount of potion in the cauldron. However, when reloading the game, placing the same potion into a cauldron already containing the potion will cause the 'explosion when mixing to potions together' event.

Steps to Reproduce:

1. Place down a cauldron.
2. Place any splash potion in the cauldron. Any amount will do.
3. Quit the game. Re-open the game.
4. Try to put the same splash potion into the cauldron.

Result:
The explosion event will occur when trying to put the exact same potion in the cauldron.