Thank you for your reply. Indeed I saved 5 rewards so I can beat villains quicker when the mission pops up in the heatwave, I didnt know there is a limit as I never had to do that before.
I did however claim them all right before the new day started (10 mins before), so I had 0 unclaimed and no contest popped up. Nonetheless I dont mind waiting a day, I just didnt know whats happening.
Thanks again.