Hello,
I having issues with admob ads only in my apps in Amazon.
The Ads has been working fine since the apps has been published.
But since 27 Nov 2018, my "Impressions" and "Match Rate" dropped to zero from one day to another, however, "AdMob Network requests" has remained.
The apps have not been updated in this period of time.
I did several tests between them, I upload the apk to "App Testing Service" and then installed from Amazon AppStore but ads does not work, the message I received is "No Filled".
Then I installed directly apk and the ads works fine.
Seems that something is blocking the ads downloading.
Thanks for your help.