I don't know the correct way to report bugs, but there's a chance that after a Deep Dive Dash round ends, it doesn't give any rewards, and it doesn't show any leaderboard. When it ends, it abruptly presents a popup that prompts the player if they want to start another round.
I got scammed out of the gold bars from placing first in the first completion of the final round.
If someone could forward this to the devs, it would be greatly appreciated.