Sulfer Cube can bounce by its self even when there is a block inside of it.

When placing an item inside the Sulfer Cube, occasionally, the Sulfer Cube can start bouncing by its self forever until the game is restarted.
Steps to Reproduce:

1. Get a Sulfer Cube.

2. Try to place a block into the Sulfer Cube.

3. Observe the Sulfer Cube bounce after the block has been placed.

Observed Result:
The Sulfer Cube still bounces by itself when there is a block inside of it.
Expected Result:
It should not move by itself.