Hi Germain,
Thank you for reaching out to us.
With regard to your concern, we don't have the ability to resend the notification as this might be only sent in your account side. However, you may check our release notes (https://developers.google.com/admob/ios/rel-notes) for the latest SDK. In addition to that, if your ads are not showing, you may provide us the following information below for us to check it also.
Mobile Ads SDK Team |