Question low fill rate banners

Hello,
I implemented unity mediation two weeks ago with banners and a reward ad.

With the reward ad, I'm getting a 92% fill rate on IOS and 72% on android

But with banners, I'm getting 1.34% for Android and 7.83% for ios. any idea why?

here is the code with some screenshots:

Code (CSharp):

1. using System;
2. using UnityEngine;
3. using Unity.Services.Core;
4. using Unity.Services.Mediation;
5. using UnityEngine.Assertions.Must;
6.  
7.  
8. public class AdBanner : MonoBehaviour
9. {
10.     [Header("Ad Unit Ids"), Tooltip("Android Ad Unit Ids")]
11.     public string androidAdUnitId;
12.  
13.     [Tooltip("iOS Ad Unit Ids")] public string iosAdUnitId;
14.  
15.     [Header("Game Ids"),
16.      Tooltip("[Optional] Specifies the iOS GameId. Otherwise uses the dashboard provided GameId by default.")]
17.     public string iosGameId;
18.  
19.     [Tooltip("[Optional] Specifies the Android GameId. Otherwise uses the dashboard provided GameId by default.")]
20.     public string androidGameId;
21.  
22.     [Header("Banner options")] public BannerAdAnchor bannerAdAnchor = BannerAdAnchor.TopCenter;
23.  
24.     public BannerAdPredefinedSize bannerSize = BannerAdPredefinedSize.Banner;
25.  
26.     IBannerAd m_BannerAd;
27.  
28.     public RectTransform topContainer, topStackView, topShadow;
29.  
30.     async void OnEnable()
31.     {
32.         try
33.         {
34.             Debug.Log("Initializing...");
35.             if (UnityServices.State == ServicesInitializationState.Uninitialized)
36.             {
37.                 await UnityServices.InitializeAsync(GetGameId());
38.             }
39.  
40.             Debug.Log("Initialized!");
41.  
42.             InitializationComplete();
43.         }
44.         catch (Exception e)
45.         {
46.             InitializationFailed(e);
47.         }
48.     }
49.  
50.     void OnDisable()
51.     {
52.         m_BannerAd?.Dispose();
53.         ResetTop();
54.     }
55.  
56.     private void ResetTop()
57.     {
58.         topContainer.sizeDelta = new Vector2(0, 171);
59.         topStackView.offsetMax = new Vector2(0, 0);
60.         topStackView.offsetMin = new Vector2(0, 0);
61.         topShadow.offsetMax = new Vector2(0, -172);
62.     }
63.  
64.     InitializationOptions GetGameId()
65.     {
66.         var initializationOptions = new InitializationOptions();
67.  
68. #if UNITY_IOS
69.         if (!string.IsNullOrEmpty(iosGameId))
70.         {
71.             initializationOptions.SetGameId(iosGameId);
72.         }
73. #elif UNITY_ANDROID
74.                 if (!string.IsNullOrEmpty(androidGameId))
75.                 {
76.                     initializationOptions.SetGameId(androidGameId);
77.                 }
78. #endif
79.  
80.         return initializationOptions;
81.     }
82.  
83.     void InitializationComplete()
84.     {
85.         // Impression Event
86.         MediationService.Instance.ImpressionEventPublisher.OnImpression += ImpressionEvent;
87.  
88.         var bannerAdSize = bannerSize.ToBannerAdSize();
89.  
90.         switch (Application.platform)
91.         {
92.             case RuntimePlatform.Android:
93.                 m_BannerAd = MediationService.Instance.CreateBannerAd(androidAdUnitId, bannerAdSize, bannerAdAnchor);
94.                 break;
95.             case RuntimePlatform.IPhonePlayer:
96.                 m_BannerAd = MediationService.Instance.CreateBannerAd(iosAdUnitId, bannerAdSize, bannerAdAnchor);
97.                 break;
98.             case RuntimePlatform.WindowsEditor:
99.             case RuntimePlatform.OSXEditor:
100.             case RuntimePlatform.LinuxEditor:
101.                 m_BannerAd = MediationService.Instance.CreateBannerAd(
102.                     !string.IsNullOrEmpty(androidAdUnitId) ? androidAdUnitId : iosAdUnitId, bannerAdSize,
103.                     bannerAdAnchor);
104.                 break;
105.             default:
106.                 Debug.LogWarning("Mediation service is not available for this platform:" + Application.platform);
107.                 return;
108.         }
109.  
110.         Debug.Log("Initialized On Start! Loading banner Ad...");
111.         LoadAd();
112.     }
113.  
114.     async void LoadAd()
115.     {
116.         try
117.         {
118.             await m_BannerAd.LoadAsync();
119.  
120.             AdLoaded();
121.         }
122.         catch (LoadFailedException e)
123.         {
124.             AdFailedLoad(e);
125.         }
126.     }
127.  
128.     void AdLoaded()
129.     {
130.         try
131.         {
132.             topContainer.sizeDelta = new Vector2(0, topContainer.sizeDelta.y + m_BannerAd.Size.Height);
133.             topStackView.offsetMax = new Vector2(0, -m_BannerAd.Size.Height);
134.             topStackView.offsetMin = new Vector2(0, -m_BannerAd.Size.Height);
135.             var offsetMax = topShadow.offsetMax;
136.             offsetMax = new Vector2(offsetMax.x, offsetMax.y - m_BannerAd.Size.Height);
137.             topShadow.offsetMax = offsetMax;
138.             topShadow.sizeDelta = new Vector2(0, 16);
139.         }
140.         catch (Exception e)
141.         {
142.             m_BannerAd?.Dispose();
143.             ResetTop();
144.             throw;
145.         }
146.  
147.  
148.         Debug.Log("Ad loaded");
149.     }
150.  
151.     void AdFailedLoad(LoadFailedException e)
152.     {
153.         Debug.Log("Failed to load ad");
154.         Debug.Log(e.Message);
155.     }
156.  
157.     void ImpressionEvent(object sender, ImpressionEventArgs args)
158.     {
159.         var impressionData = args.ImpressionData != null ? JsonUtility.ToJson(args.ImpressionData, true) : "null";
160.         Debug.Log($"Impression event from ad unit id {args.AdUnitId} : {impressionData}");
161.     }
162.  
163.     void InitializationFailed(Exception error)
164.     {
165.         var initializationError = SdkInitializationError.Unknown;
166.         if (error is InitializeFailedException initializeFailedException)
167.         {
168.             initializationError = initializeFailedException.initializationError;
169.         }
170.  
171.         Debug.Log($"Initialization Failed: {initializationError}:{error.Message}");
172.     }
173. }

ios:



Android: