Wizard Cards rewards are still broken

Wizard Cards seems to still be broken. I completed two collections by opening 10 cards at a time, and both times, when I opened what I can just assume to be the last card of their respective collection, the small message-window enters in a never-ending loading loop. There is no pop up announcing that the collection is finished. I got my leveling-up notification on the background, so that part works well. But there is no prize (object or pet), although the collection is obviously finished. I stopped before missing the /sing prize, hoping that it will be fixed.