Platform, device version and operating system:
Mobile, Samsung Galaxy A40, Android 10
Screenshot or image:
You can see the button flash when I tap it, and nothing happening in response.
What you were expecting to happen, and what actually happened:
I expected the rewarded ad to play, but nothing happened when I pressed the button.
How often does this happen? When did it begin happening?
I think it started happening with 5.0. It happens to me once in three days, on average (I leave the app in background a lot).
Steps to make it happen again
Leave the app open in background, and return to it after some time, when the wait time for a new ad expired. Try to play the ad as usual, and nothing will happen. The longer the app remains in background, the more likely the issue is to occur, in my experience. Restarting the app allows to play the ad normally.