Google Ads suddenly stopped working after few months [Android][iOS][Flutter]

I had banner, interstitial, and reward ads on one of my apps. The ads seemed to have been working for the past 2 months and then suddenly yesterday both android and iOS apps stopped showing ads:

iOS Error: code: 1, domain: com.google.admob, message: Request Error: No ad to show

Android: code: 3, domain: com.google.android.gms.ads, message: No ad config

It's also strange that both the apps have different error codes.

Package: google_mobile_ads: ^0.12.1+1

Code:

Container(
     height: bannerAd.size.height.toDouble(),
     child: AdWidget(
            ad: bannerAd,
            ),
     margin: EdgeInsets.symmetric(vertical: 30),
)

Note:

1. The test ads seem to work just fine.
2. The Android and iOS apps have been published on the stores and have been working just fine for the past 2 months.

from Google Ads suddenly stopped working after few months [Android][iOS][Flutter]