New Expansion Question

I have purchased and download the Minotaur expansion and signed on with one my accounts and played successfully.

However, I also have three other accounts when I go sign on to the new client with one of them I am being asked to again purchase it for $19.99.

Now I have the executable setup files in my computer, is it just a matter of running the setup again and signing into with other accounts?

I dont remember purchasing 4 Catacombs or 4 of the next expansion in the past.

Anyone have any insight?