Failed to load interstitial ad with error: Request Error: No ad to show

Environment
SDK Version: 13.2.0 (via SPM)[https://github.com/googleads/swift-package-manager-google-mobile-ads.git]

Xcode Version: 26.0

Platform: iOS

Ad Format: Interstitial

Issue Description
I am encountering a persistent "Request Error: No ad to show" when running my app in a production environment. The implementation works perfectly in Debug mode (using test ad unit IDs), where ads load and display as expected. However, once switched to production Ad Unit IDs and deployed, the load request fails consistently.

Full error log

Error Domain=com.google.admob Code=1 "Request Error: No ad to show." UserInfo={NSLocalizedDescription=Request Error: No ad to show.

Implementation Code

InterstitialAd.load( with: "<INTERSTITIAL_ADS_UNIT_ID>", request: request, completionHandler: { [weak self] ad, error in guard let self = self else { return } if let error = error { print("[AdManager] Failed to load interstitial ad with error: \(error.localizedDescription)") return } // Ensure UI updates happen on main actor DispatchQueue.main.async { self.interstitial = ad self.interstitial?.fullScreenContentDelegate = self print("[AdManager] Interstitial ad loaded successfully") } } )

Troubleshooting Steps Taken

App ID/Ad Unit ID Verification: Confirmed that the IDs match the AdMob dashboard exactly.​

Test Devices: Verified that the behavior persists across different physical devices.

App Store Status: The app is linked to the AdMob dashboard and the app-ads.txt is verified ​and "Authorized."

Payments/Policy: No policy violations or payment holds are present in the AdMob console.

​Thanks in advance