Banner SetPosition works in editor but not working in published game

Hi,
I implemented my banner like below:

Code (CSharp):

1. IEnumerator LoadAds()
2. {
3.         //wait for ad init
4.         while (!Advertisement.isInitialized)
5.         {
6.             yield return null;
7.         }
8.         //banner laod
9.         BannerLoadOptions loadOptions = new BannerLoadOptions
10.         {
11.             loadCallback = OnBannerLoaded,
12.             errorCallback = OnBannerError
13.         };
14.         Advertisement.Banner.Load(bannerPlacementId, loadOptions);
15.  
16.         //rewarded load
17.         Advertisement.Load(rewardedPlacementId);
18.         //video load
19.         Advertisement.Load(videoPlacementId);
20. }
21.  
22. IEnumerator PrepareBannerToShow()
23.  {
24.         while (!Advertisement.Banner.isLoaded)
25.         {
26.             yield return null;
27.         }
28.  
29.         while (!Advertisement.IsReady(bannerPlacementId))
30.         {
31.             yield return null;
32.         }
33.  
34.         Advertisement.Banner.Show(bannerPlacementId);
35.         Advertisement.Banner.SetPosition (BannerPosition.TOP_CENTER);
36. }

Banner ads and positioning working well in test mode in the editor. In device testings, I noticed that the banner started in the bottom then 20-30 seconds after changed its position to top-center. So, I thought that would be an issue because of test ads.

Today my game published on google play here is the link:
https://play.google.com/store/apps/details?id=com.pinuscraft.VillageDefence

I've tested on two different devices and banner ad loading but sitting on bottom only. And I noticed, sometimes does not load at all.

Can anyone help me with this?