Fatal Exception: android.content.ActivityNotFoundException | android.gms.ads.AdActivity (ADMOB)

Question

Since today at an amazing speed Admob is crashing when trying to display an Add according to Firebase.

Also Crashlytics is not getting the mapping... do not know why

This happens in every version of android 4, 5, 6, 7, 8, 9, 10.

Fatal Exception: android.content.ActivityNotFoundException Unable to find explicit activity class {com.myCompany.myApp/com.google.android.gms.ads.AdActivity}; have you declared this activity in your AndroidManifest.xml? com.myCompany.myApp.GameActivity.E

android.app.Instrumentation.checkStartActivityResult (Instrumentation.java:1933)
android.app.Instrumentation.execStartActivity (Instrumentation.java:1616)
android.app.ContextImpl.startActivity (ContextImpl.java:904)
android.app.ContextImpl.startActivity (ContextImpl.java:882)
android.content.ContextWrapper.startActivity (ContextWrapper.java:383)
com.google.android.gms.internal.ads.Di.a (Unknown Source:9)
com.google.android.gms.ads.internal.overlay.zzn.a (Unknown Source:77)
com.google.android.gms.internal.ads.KC.a (Unknown Source:76)
com.google.android.gms.internal.ads.zu.a (Unknown Source:9)
com.google.android.gms.internal.ads.cF.showInterstitial (Unknown Source:24)
com.google.android.gms.internal.ads.Cea.c (Unknown Source:7)
com.google.android.gms.ads.InterstitialAd.c (Unknown Source:2)
com.myCompany.myApp.GameActivity.E (Unknown Source:82)
com.myCompany.myApp.X.onClick (Unknown Source:4)
android.view.View.performClick (View.java:6390)

Tried to reproduce the error locally, but couldn't This started suddenly... and is in the only app that I'm getting that error in Firebase (all are implemented the same way)

Gradle

dependencies {
...
    implementation 'com.google.android.gms:play-services-ads:18.2.0'
    implementation 'com.google.firebase:firebase-core:17.2.0'
    implementation 'com.crashlytics.sdk.android:crashlytics:2.10.1'  
...
}

MANIFEST

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.myCompany.MyApp"
          android:installLocation="auto">

<uses-permission android:name="android.permission.VIBRATE"/>  
<uses-permission android:name="android.permission.INTERNET"/>  
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.WAKE_LOCK"/>

    <supports-screens
        android:anyDensity="true"
        android:largeScreens="true"
        android:normalScreens="true"
        android:resizeable="true"
        android:smallScreens="true"
        android:xlargeScreens="true"
        />

    <application
        android:allowBackup="true"
        android:fullBackupContent="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:largeHeap="true"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        >

        <uses-library
            android:name="org.apache.http.legacy"
            android:required="false"/>
        <meta-data
            android:name="com.google.android.gms.ads.AD_MANAGER_APP"
            android:value="true"/>
        <meta-data
            android:name="com.google.android.gms.ads.APPLICATION_ID"
            android:value="THENUMBERFORMYADMOB"/>
        <service
            android:name=".services.MusicService"
            android:enabled="true"/>

        <meta-data
            android:name="firebase_crashlytics_collection_enabled"
            android:value="${crashlyticsCollectionEnabled}" />

        <activity
            android:name=".SplashActivity"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <action android:name="android.intent.action.VIEW"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
        <activity
            android:name=".LevelsActivity"
            android:label="@string/title_activity_game"
            android:parentActivityName=".SplashActivity">
        </activity>
        <activity
            android:name=".GameActivity"
            android:keepScreenOn="true"
            android:label="@string/title_activity_game"
            android:parentActivityName=".LevelsActivity">
        </activity>

        ...
        OTHER ACTIVITIES
        ...


    </application>
</manifest>

I implemented Admob accordingly to the guide. ¿Should I add an Admob activity?

In google play crash report I'm getting reports regarding

signal 11 (SIGSEGV), code 1 (SEGV_MAPERR) WebViewGoogle.apk

  #00  pc 00000000008fca14  /system/app/WebViewGoogle/WebViewGoogle.apk

But this has been for a long time (since 1' July... when started suddenly with a spike...) and google is "fixing it"... could this be related?