Sulphur Cube Issue

I was playing on Bedrock mode with experimental features on, and I was experimenting with Sulphur Cubes. When I put Magma into a Sulphur Cube, it worked, but the Sulphur Cube infused with Magma would not do damage to any nearby mob. I also tried to put TNT in another Sulphur Cube, but the Sulphur Cube would not accept it.