What I expected to happen was:
To get my dirt back when I break it.

What actually happened was:
The dirt vanished.

Steps to Reproduce
1. Log into a survival world.
2. Start walking around for a little bit, preferably to a different chunk than the one you loaded in.
3. Notice that the blocks you break will not give it back, and the only way to break blocks and get them back is to quit the game and come back.
Video
https://www.youtube.com/watch?v=x-MMMDK_QhE&feature=youtu.be