Mana Curve is Really Bugged!

First of all, thanks to Flux and his team bringing out a-must feature, which is sweet. However, as much as I loved it, it seems that new feature is bugged, seen here: I have three 6-Cost cards, yet mana curve shows there are none of it. I checked my other decks, then people's decks, and I saw this issue everywhere. I think of a reason why, but not sure: Dust calculation errors were related as if duplicates were calculated as one card. Maybe that's the case here? Hope you guys/gals check mana curve issue, I believe in all of you.

I can assure that you are correct, Chimera. Here, all cards are class cards and are counted.