Unity ad Banner not showing in production

Hi, i used the code from official unity integration guide and i created the placement too. The test banner show correctly, but when i submit the apk in Google Play, the ad not showing in devices.

The code used:

	void Start()
	{
		Advertisement.Initialize(ShareData.instance.gameId, ShareData.instance.testMode);
		StartCoroutine(ShowBannerWhenReady());
	}

	IEnumerator ShowBannerWhenReady()
	{
		while(!Advertisement.IsReady(ShareData.instance.placementIdBanner))
		{
			yield return new WaitForSeconds(0.5f);
		}

		Advertisement.Banner.Show(ShareData.instance.placementIdBanner);
	}

Any idea?.

did you ever figure this out?