Guardians, BF, Elder Wraiths' "glitched" KB intentional?

For whatever reason, Brandish hits Elder Wraiths in their invincible frame.

I can use my Chief Bandit to pretty much hit them non stop. It takes quite a lot of skills, but it is highly possible. And I wouldn't be surprised if it works for any job.

On topic; I dunno really if you guys have realized it, but even Krips in Aqua Road has this "glitched" KB. I haven't even noticed this until a couple of weeks ago. Earlier, I've always thought that it was something like the position I was attacking from that was messing me up x.x

Then sometime after the release of CWK, I went to do some quest in Aqua Road. I then realized that they also are affected by it.