Tavern Brawl Bug

So i’ve recently been playing the new brawl, when i wanted to clear the deck, hearthstone asked me to autocomplete with 1 card remaining (i had 0/30)
That intrigued me so i tried making a deck with only 1 card in my deck. I was able to search for a match.
Turns out Hearthstone autoincluded cards in my deck, but thats not even the best part. It included cards from the whole pool of HS cards, and not the ones i had in my library.
Even further, it gave me cards that DONT EVEN EXIST IN THE GAME. No voicelines, animations etc. cards that devs use for testing. I managed to get stuff like: pre-nerfed knife juggler, avatar of coin (0 mana 1/1 text: you lost the coin flip, but you gained a friend.), a litterall cardback as a card, heropowers as cards, a fully complete diamond spellstone, gilean royal guard in the 8/3 statline and the priest ‘elixir of shadows’ (its normally called undefined elixir and becomes something random, but it came in the shadow form from the start)
I dont include screenshots because it’s super easy to replicate in-game.
Edit: I remember i also got a wierd 4 mana 4/4 without text, i dont remember what it was called but i know that it didnt have voicelines and it was not a ‘real’ card