diff --git a/Disco.Services/Devices/ManagedGroups/DeviceBatchAssignedUsersManagedGroup.cs b/Disco.Services/Devices/ManagedGroups/DeviceBatchAssignedUsersManagedGroup.cs
index f2c74c57..aedd9648 100644
--- a/Disco.Services/Devices/ManagedGroups/DeviceBatchAssignedUsersManagedGroup.cs
+++ b/Disco.Services/Devices/ManagedGroups/DeviceBatchAssignedUsersManagedGroup.cs
@@ -57,7 +57,7 @@ namespace Disco.Services.Devices.ManagedGroups
             repositorySubscription = RepositoryEvents.Value
                 .Where(e =>
                     (((Device)e.Entity).DeviceBatchId == DeviceBatchId) ||
-                    (e.EventType == RepositoryMonitorEventType.Modified && e.GetPreviousPropertyValue<int>("DeviceBatchId") == DeviceBatchId))
+                    (e.EventType == RepositoryMonitorEventType.Modified && e.GetPreviousPropertyValue<int?>("DeviceBatchId") == DeviceBatchId))
                 .Subscribe(ProcessRepositoryEvent);
         }
 
diff --git a/Disco.Services/Devices/ManagedGroups/DeviceBatchDevicesManagedGroup.cs b/Disco.Services/Devices/ManagedGroups/DeviceBatchDevicesManagedGroup.cs
index 3d2f0c6a..71e9f961 100644
--- a/Disco.Services/Devices/ManagedGroups/DeviceBatchDevicesManagedGroup.cs
+++ b/Disco.Services/Devices/ManagedGroups/DeviceBatchDevicesManagedGroup.cs
@@ -55,7 +55,7 @@ namespace Disco.Services.Devices.ManagedGroups
             repositorySubscription = RepositoryEvents.Value
                 .Where(e =>
                     (((Device)e.Entity).DeviceBatchId == DeviceBatchId) ||
-                    (e.EventType == RepositoryMonitorEventType.Modified && e.GetPreviousPropertyValue<int>("DeviceBatchId") == DeviceBatchId))
+                    (e.EventType == RepositoryMonitorEventType.Modified && e.GetPreviousPropertyValue<int?>("DeviceBatchId") == DeviceBatchId))
                 .Subscribe(ProcessRepositoryEvent);
         }
 
diff --git a/Disco.Web/Areas/API/Controllers/DeviceBatchController.cs b/Disco.Web/Areas/API/Controllers/DeviceBatchController.cs
index 36755cee..003fc0a6 100644
--- a/Disco.Web/Areas/API/Controllers/DeviceBatchController.cs
+++ b/Disco.Web/Areas/API/Controllers/DeviceBatchController.cs
@@ -500,7 +500,7 @@ namespace Disco.Web.Areas.API.Controllers
                 DeviceBatch.AssignedUsersLinkedGroup = configJson;
                 Database.SaveChanges();
 
-                var managedGroup = DeviceBatchDevicesManagedGroup.Initialize(DeviceBatch);
+                var managedGroup = DeviceBatchAssignedUsersManagedGroup.Initialize(DeviceBatch);
                 if (managedGroup != null) // Sync Group
                     return ADManagedGroupsSyncTask.ScheduleSync(managedGroup);
             }