I am using an Android platform to play MTG Arena. When I attempt to complete a Brawl deck build with 9 Nazgul creature cards, I get an error stating that "there are too many copies of a card in the deck". The Nazgul creature card has a rule that allows me to use 9 copies of it within a deck, so my deck should be completed and valid. It only becomes valid when I reduce the number of Nazgul creature cards to 1.

The " allowed up to X in a deck" creature card rule isn't working properly at the moment, and is making a few of my Brawl decks invalid. Other cards with the same rules as the Nazgul creature card aren't working as well, such as the Rat Colony or Hare Apparent creature card.