Hi, I think this DLC is a special case.

From the product page, it doesn't show "GAME_TITLE is already in your Steam library" message and is still on my wishlist. But I also can't redeem it, it shows "This Steam account already owns the product."

I checked SteamDB and confirmed that I actually have this DLC. Please reroll it, and I'll hide this DLC from SG to avoid entering it again.

Thank you!