Whenever you mine a block in a Customized World map there is an extreme lag in the time it takes for you to mine a block and for the game to realize it.

For example, when a I mine a stone block it takes enough time for me to re-mine that block twice before it pops out of the ground. The block reappearing every time it should pop out until then.

Steps to Reproduce:
1. Open a world with the customized world type (any preset should do)
2. take a pick
3. try to mine some stone.