firebase - Android Studio: Google Admob Interstitial test ad works only partially

Question

I have a problem while using the test Interstitial ad from Google Admob on my virtual devices. It is working only partially. It works fine on my virtual devices Nexus S (API 21), Nexus 9 (API 29) and Pixel 2 (API 30), but not for Nexus 6 (API 22) and Nexus 9 (API 22). I have also deimplemented and implemented the 2 not working virtual devices, but they are still not working and I got the following message: "W/Ads: Invoke Firebase method getInstance error. The Google Mobile Ads SDK will not integrate with Firebase. Admob/Firebase integration requires the latest Firebase SDK jar, but Firebase SDK is either missing or out of date"

"W/Ads: Invoke Firebase method getInstance error.
    The Google Mobile Ads SDK will not integrate with Firebase. Admob/Firebase integration requires the latest Firebase SDK jar, but Firebase SDK is either missing or out of date"

Answer 1

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