Blocks do not always break with activated shield

In the Creative version of Minecraft Windows 10, it does not always break blocks with an active shield in hand.

How to reproduce:

1. Take the shield in your hand.
2. Activate the shield by pressing the Shift key.
3. Start breaking nearby blocks (hold the Shift key!).

Expected results:
The blocks will break.

Observed results:
Sometimes the blocks don't disappear. (may not work the first time)

Videos:
Windows 10.mp4