When in creative mode on Windows 10 Edition, breaking using a mouse sometimes causes spam click with breaking as if it is intermitting. It also can be done by holding down leftclick and dragging over certain block types.

Best results are when moving diagonally. Sometimes happens when stationary.

This has been reproduced using these blocks:

• Glass
• Grass
• Leaves
• Tall Grass
  Seems to be on most of the "softer" blocks.