How to Trigger and there are 2 ways to do this and this has been going on for a LONG time:

NOTE: This doesn't happen on the first try, so just try it a couple times and it will work.

First way:
1. Get a sword (Any sword)
2. Start hitting a block (Do a simple one, like dirt or grass)
3. Now use the block technique and then keep hitting again and then block, etc.
4. Just keep doing that and it should keep the breaking marks until you break the block.
5. That's it

Second way:
1. Have anything in your hand, or you can just use your hand
2. Start hitting a simple block (Again, dirt or grass)
3. Now hold your left mouse button and look away and don't hit anything else.
4. Go back to that block you were hitting and start hitting it again
5. Look away again and you'll see that the breaking on the block is still there.
6. Keep on going till the block breaks.
7. And you're done!

So those are bugs that I've been seeing since I ever got Minecraft. I don't know if anybody else reported this or is having this problem, but I just wanted to report it. Hope this makes a difference to 1.8.9, 1.8.10 or 1.9

Also, there is a video showing you what it looks like in the attachment.