Game bug on Teamfight Tactics

There is a bug i found in Teamfight Tactics. My champion "inventory", should i call it, was full and i had 6 out of 6 champions in the "board", ready to fight. I was level 6. Then the event where everybody chooses a new champion happened and when i got a champion it put it in the "board" and it was saying 7/6 champion. I don't know if I explained it correctly, but let me know if there is anything you don't understand.