Why does the Google Maps API work in the APK release, but it doesn’t show the map in the APK loaded in the Beta open testing store?

Question

In APK release key goes. In store APK does not show the map. Follow the manifest:

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="br.com.blablabla.blablabla.android" android:installLocation="auto" android:versionName="1.0.1.0" android:versionCode="1010">
<uses-sdk android:minSdkVersion="22" android:targetSdkVersion="27" />
<permission android:name="br.com.blablabla.blablabla.android.permission.MAPS_RECEIVE" android:protectionLevel="signature"></permission>
<uses-permission android:name="br.com.blablabla.blablabla.permission.MAPS_RECEIVE" />
<!-- We need to be able to download map tiles and access Google Play Services-->
<uses-permission android:name="android.permission.INTERNET" />
<!-- Allow the application to access Google web-based services. -->
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
<!-- Google Maps for Android v2 will cache map tiles on external storage -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<!-- Google Maps for Android v2 needs this permission so that it may check the connection state as it must download data -->
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<!-- They will allow Maps to use the My Location provider. -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<!-- Camera also need Storage. -->
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.location" android:required="true" />
<uses-feature android:glEsVersion="0x00020000" android:required="true" />
<application android:allowBackup="true" android:label="@string/app_name" android:icon="@drawable/icon" android:theme="@style/android:Theme.Holo.Light">
    <!-- Put your Google Maps V2 API Key here. -->
    <meta-data android:name="com.google.android.geo.API_KEY" android:value="AIzaSyCfBlablablablabla... aqui está minha chave de API e as duas assinaturas de keystore estão lá nas credenciais restringindo Apps para Androi. Uma assinatura de debug do Xamarin e uma de release." />
    <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" />
    <provider android:name="android.support.v4.content.FileProvider" android:authorities="${applicationId}.fileprovider" android:exported="false" android:grantUriPermissions="true">
        <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/file_paths"></meta-data>
    </provider>
</application>

Here is the map XAML:

...
<maps:Map x:Name="blablabla"
  HeightRequest="165"
  HorizontalOptions="FillAndExpand"
  IsShowingUser="True"
  MapType="Street"
  HasZoomEnabled="True"
  HasScrollEnabled="True"/>
...

Also use in c# like this:

...
// Main Map:
      blablabla = new Map(
      MapSpan.FromCenterAndRadius(new 
          Position(AppPosition.Latitude,
          AppPosition.Longitude),Distance.FromMiles(0.3)))
              {
                 IsShowingUser = true,
                 MapType = MapType.Street,
                 HasZoomEnabled = true,
                 HasScrollEnabled = true,
                 HeightRequest = 170,
                 //VerticalOptions = LayoutOptions.FillAndExpand
                 //WidthRequest = 960,
                 HorizontalOptions = LayoutOptions.FillAndExpand
              };
      StackMarmitaMap.Children.Clear();
      StackMarmitaMap.Children.Add(blablabla);

Where am I wrong? Thank you.