Hi,
using new Rewarded Api works on your new simple example, but not at the more complex older project.
It looks like
implementation 'com.google.android.gms:play-services-ads:18.2.0'
makes problems with older libraries and i am able to use only 16.0.0 version now, without a compilation error.
It is probably because androidx.
ERROR: Manifest merger failed : Attribute application@appComponentFactory value=(android.support.v4.app.CoreComponentFactory) from [com.android.support:support-compat:28.0.0] AndroidManifest.xml:22:18-91
is also present at [androidx.core:core:1.0.0] AndroidManifest.xml:22:18-86 value=(androidx.core.app.CoreComponentFactory).
Suggestion: add 'tools:replace="android:appComponentFactory"' to <application> element at AndroidManifest.xml:22:5-82:19 to override.
I was looking for, how to solve this problem browsing internet,but nothing works for me, only to use older 16.0.0 version and older Rewarded API.