I want to display AdMob fullscreen ads within my game. So I have downloaded the latest GoogleMobileAds-v5.4.0 unity package for my game.
But to my surprise, I can't able to get real ads from AdMob though Test Ads working fine.
In XCode Log, I was getting this kind of error messages:

I have created a demo project, just to test ads and no collision with other plugins can occur but the result is the same.
From first to last, I was following this document to implement AdMob ads: Get Started Google AdMob
I have mostly read other threads that are posted for the same problem but I can't able to find something that becomes useful so I decided to create a separate question with full information provided.
Share your knowledge if you have any idea for this kind of problem. One more thing, My AdMob account is not new, I was using it for last 6 months.
