Hi Marouan,
Thank you for providing the Ad Unit IDs. I was able to load ads by testing your Ad Unit ID with our
sample apps. Since you're receiving no ad to show when the Bundle Identifier is changed, this could be an issue with your Bundle ID. I'd suggest that you contact the AdMob Product Support team and provide them the new and old Bundle IDs, so they can take a look and resolve the issue. You can contact them via the Contact Us button on the upper right corner of
this page or use
this troubleshooter to submit a request.