NO daily quest displays at quest log, But I can still do the quest and get the reward

I start my hearthstone game on window 10 and through Hearthstone Deck Tracker.
I don’t know whether HDT causes the bug.

No daily quest pop up while I start the game software.
I played my mage deck in Play mode.
After I played 4-5 games, suddenly I got a 50 Golds reward from daily quest “Mage or Shaman Victory”.
Is this a bug or what?