Place blocks very fast

How to reproduce the bug
1. Grab any block.
2. Stay in a clear place to place the blocks.
3. If you place the blocks in straight line, the blocks will be placed very fast than the normal (the bug). But, if you place the blocks in diagonal line, the blocks will be placed in normal speed.

I can't show the bug on images or a video, because I couldn't publish it on Twitter.