Originally Posted by maotd

Bonus stages are broken too. I unlocked 1st flag stage during my 1st clear of the 80stam mission and... the bonus stage timer started and count down during the final scene of the event. Result, bonus stage appears at the end... with a 0 second timer. Well done. And that's not the first time.

That's the same as to afk during a mission, come back on the score screen with the completion rewards, and then the bonus stage appears with the timer already down.