StoreKit in IOS 18

I have has a the Storekit working in my application previously.

It uses the a iTunes songs ID and allows the user to purchase the track from iTunes within the app using a View.

its been fine in IOS 17 but since the update to 18 Ive not been able to get this to work.

the iTunes panel loads within the app and shows the track I wish to purchase. on clicking purchase I login with my Apple ID password. that then spins for a few seconds then asks to do the purchase again.

Can you please advise.

code below

        print ("Store ID + \(self.appId)")
        let storeProductViewController = SKStoreProductViewController()
        storeProductViewController.delegate = self
        
        let parameters = [SKStoreProductParameterITunesItemIdentifier: self.appId]
        storeProductViewController.loadProduct(withParameters: parameters) { status, error -> Void in
            if status {
                self.present(storeProductViewController, animated: false, completion: nil)
                print("success: \(status.description)")
            } else {
                if let error = error {
                    print("Error: \(error.localizedDescription)")
                }
            }
        }
        
      DispatchQueue.main.async {
            self.isPresentStoreProduct.wrappedValue = false
        }
    }