My friend and I have recently started to play MTGA (Steam version) and both of us are going with the New Player quests (I suppose what that quest line is). One of them for me was to play 5 unranked Alchemy games to receive a random beginner Brawl deck. I completed it and have not received the deck. However my friend didn't even have the same quest, he never played Alchemy, he was just playing Spark ranked to unlock different formats and after a random win, he randomly received a starter Brawl deck.
Happened on the 27th of Sept. 2024.