Hello and thank you a lot for your fast response.
So I was trying different things today without success.
I updated all SDKs through the SDK Manager.
I reimported Firebase and google services.
I forced the android resolver.
I double-checked the code.
Attached you can find my logcat. I just printed all to see everything going on but I cannot figure out why exactely the app is crashing. Maybe you can see the problem. I started the video at around 22:13:30 and it had been loaded at around :34 . Then I clicked the close button and yes close video on the popup at around :40. After that the ad disappears shows the game again but the screen is not updating anymore eventhough the script goes on because it triggers "end Loading" which is a debug.log in a custom trigger function to unshow the loader animation but the loader is still shown and does not show any animation. after a few short seconds the app crashes totally and asks to restart again.
I also attached my code so maybe I am doing something wrong (you can see my IDs in the code) and additionaly I implemented the HelloWorld Sample Scene in the app. This does not crash the app, so now I am not really sure what I am doing wrong. Thank you very much for your investigation and help! I am not sure what else I should do or try. I followed the documentation but something must be wrong. I used to use UnityAds which worked fine but I like AdMob more because there is more video variation, but as you can see I am having trouble implementing.
Best regards, Markus