Admob interstitial presented whitout calling presentFromRootViewController

Question

I'm using Admob interstitial in my app. I followed all the guidelines and I observe Video interstitial are presented automatically while I did not call yet presentFromRootViewController.

I'm using that code to preload the interstitial :

splashInterstitial_ = [[GADInterstitial alloc] initWithAdUnitID: interstitialIdStr];
splashInterstitial_.delegate = self;
requestInterstitial = [GADRequest request];
[splashInterstitial_ loadRequest: requestInterstitial];

In the delegate, I do not present the interstitial :

- (void)interstitialDidReceiveAd:(GADInterstitial *)ad
{
}

I present the interstitial manually between two screens, as follow :

if (splashInterstitial_.isReady)
{
   [splashInterstitial_ presentFromRootViewController: interstitialRootViewController];
    self.lastInterstitialTime = [[NSDate date] timeIntervalSince1970];
    return YES;
}

I placed a breakpoint on presentFromRootViewController, the breakpoint is never reached, and I can see interstitial videos presented on real device.

I sounds like the loadRequest on interstitial triggers a presentation which should not occur.

Anybody experiencing a similar issue ? Thanks