diff --git a/AsbCloudInfrastructure.Tests/Services/SAUB/TelemetryDataSaubCacheTests.cs b/AsbCloudInfrastructure.Tests/Services/SAUB/TelemetryDataSaubCacheTests.cs
index 53893067..7f9a76bd 100644
--- a/AsbCloudInfrastructure.Tests/Services/SAUB/TelemetryDataSaubCacheTests.cs
+++ b/AsbCloudInfrastructure.Tests/Services/SAUB/TelemetryDataSaubCacheTests.cs
@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using AsbCloudApp.Data.SAUB;
+using AsbCloudApp.Repositories;
 using AsbCloudDb.Model;
 using AsbCloudInfrastructure.Background;
 using AsbCloudInfrastructure.Services.SAUB;
@@ -14,6 +15,7 @@ namespace AsbCloudInfrastructure.Tests.Services.SAUB;
 
 public class TelemetryDataSaubCacheTests
 {
+    private static object _lock = new object();
     private const int idTelemetry = 1;
 
     private readonly IEnumerable<TelemetryDataSaubDto> fakeTelemetries = new[]
@@ -29,20 +31,22 @@ public class TelemetryDataSaubCacheTests
     public TelemetryDataSaubCacheTests()
     {
         serviceProviderMock.GetService<BackgroundWorker>().Returns(new BackgroundWorker(serviceProviderMock));
-
         telemetryDataCache = TelemetryDataCache<TelemetryDataSaubDto>.GetInstance<TelemetryDataSaub>(serviceProviderMock);
-
         telemetryDataCacheType = telemetryDataCache.GetType();
+
     }
 
     [Fact]
     public void AddRange_ShouldReturn_AddedElementToCache()
     {
         //arrange
-        telemetryDataCacheType.GetField("isLoading", BindingFlags.NonPublic | BindingFlags.Instance)?.SetValue(telemetryDataCache, false);
+        telemetryDataCache.AddRange(idTelemetry, fakeTelemetries);
+        
+        telemetryDataCacheType
+        .GetField("isLoading", BindingFlags.NonPublic | BindingFlags.Instance)!
+        .SetValue(telemetryDataCache, false);
 
         //act
-        telemetryDataCache.AddRange(idTelemetry, fakeTelemetries);
         var lastTelemetry = telemetryDataCache.GetLastOrDefault(idTelemetry);
 
         //assert
@@ -53,10 +57,12 @@ public class TelemetryDataSaubCacheTests
     public void AddRange_ShouldReturn_NotAddedToCache()
     {
         //arrange
-        telemetryDataCacheType.GetField("isLoading", BindingFlags.NonPublic | BindingFlags.Instance)?.SetValue(telemetryDataCache, true);
+        telemetryDataCache.AddRange(idTelemetry, fakeTelemetries);
+        telemetryDataCacheType
+            .GetField("isLoading", BindingFlags.NonPublic | BindingFlags.Instance)!
+            .SetValue(telemetryDataCache, true);
 
         //act
-        telemetryDataCache.AddRange(idTelemetry, fakeTelemetries);
         var lastTelemetry = telemetryDataCache.GetLastOrDefault(idTelemetry);
 
         //assert
diff --git a/AsbCloudInfrastructure/Services/SAUB/TelemetryDataCache.cs b/AsbCloudInfrastructure/Services/SAUB/TelemetryDataCache.cs
index da0a9486..ddfeef7f 100644
--- a/AsbCloudInfrastructure/Services/SAUB/TelemetryDataCache.cs
+++ b/AsbCloudInfrastructure/Services/SAUB/TelemetryDataCache.cs
@@ -139,6 +139,9 @@ public class TelemetryDataCache<TDto> : ITelemetryDataCache<TDto> where TDto : A
 
     public virtual TDto? GetLastOrDefault(int idTelemetry)
     {
+        if (isLoading)
+            return default;
+
         if (!caches.TryGetValue(idTelemetry, out TelemetryDataCacheItem? cacheItem))
             return default;