Wrong information about Dalaran's adventure chapter complite

Today I bought the fifth chapter of Dalaran’s adventure. I’ve never completed it, but in the game, I have a crown under 7 heroes of 9. It can be caused by I completed all other chapters with all heroes may be.

Yes, that is it (but from chapter 1):

Will they fix it or it’s normal behavior?

I only know what is in that announcement, including this bit:

(hint: click the V button to expand the whole post)

Thank you for your support)