title: Android Studio - Rewarded Video Ad loaded but not shown
body: <p>I tried the following code (main_activity.java)</p>
  
  <pre><code>        MobileAds.initialize(this, "ca-app-pub-3940256099942544~3347511713");
  // Use an activity context to get the rewarded video instance.
          mRewardedVideoAd = MobileAds.getRewardedVideoAdInstance(this);
          mRewardedVideoAd.setRewardedVideoAdListener(this);
          loadRewardedVideoAd();
      }
  
      private void loadRewardedVideoAd() {
          mRewardedVideoAd.loadAd("ca-app-pub-3940256099942544/5224354917",
                  new AdRequest.Builder().build());
  
          if (mRewardedVideoAd.isLoaded()) {
              mRewardedVideoAd.show();
          }
  </code></pre>
  
  <p>logcat says, that the Ad is loaded but it doesn´t show up. I want to display the ad in a seperate fragment, so maybe the "(this)" is wrong?</p>
  
  <p>Thank you for your help...
  See this reference: <a href="https://developers.google.com/admob/android/rewarded-video" rel="nofollow noreferrer">https://developers.google.com/admob/android/rewarded-video</a></p>