30 Minutes of Playtime Disappeared from Dungeon Quest

I'm currently playing this game in Dungeon Quest, but the 'Play for 30 minutes' item, which used to appear multiple times a day, is no longer showing up even after the date changed. It seems like I've already completed it 😭 To defeat the dungeon monsters, I have no choice but to raise my rank somehow and clear the rank-specific objectives. Monster subjugation is getting tougher and tougher 😅 But I won't give up here and will try my best to raise my rank even a little by playing every day 💪