Had daily quest to play 5 ranked games. Finished second game, got the popup showing 2/5 completed. Went and collected last reward in Event chain. Went back to quests tab and the daily quest had vanished.
Daily quests reset at a certain time every day, right? Maybe it was just that time?
They don’t, what do you mean ?
Was that an event daily quest ? If you completed the event, your event quest will vanish since they don’t give you anything anymore
Hmm, maybe I’m mixing up Hearthstone and Warcraft. Ignore me. 
Just played a few games and I still got the popup after each games. 3/5, 4/5 and then nothing because it obviously completed, however I got zero credit for it. Nice work devs!
Again asking, was it an event related quest ? There’s no daily quest to play ranked games in the regular quests
If you already completed the event, the actual bug would be that you keep seeing the progress, not that the quest vanished. You’d have nothing to be credited for since you already maxed out what th equets rewards you with.
No, standard daily quest. I know that the event quests vanish once the chain is completed.
As I said, there are no regular daily quests to play ranked games
Only weekly quests to win ranked games
Only the event has daily quests to play ranked