Ads show up in editor but not during play test on iPhone

Hello, so my ad viewer script is on a button and when it’s pressed, the ad shows up in my editor and says everything is working properly. When I build the game to my iPhone and test it on the device, nothing happens. Is there some configuration in Xcode i’m missing? Here is the code:

	string store_id = "2997880";
	public string placementID = "RoundEnd";

	void Start()
	{

		Monetization.Initialize (store_id, true);

	}
	public void ShowAd() {
		
		if (Monetization.IsReady("RoundEnd"))
		{
			ShowAdPlacementContent ad = null;

			ad = Monetization.GetPlacementContent (placementID) as ShowAdPlacementContent;

			if (ad != null) {
				ad.Show ();

			}
	}

}

}

For some inexplicable reason it started working on my last play test.