diff --git a/src/Umbraco.Core/Services/UserService.cs b/src/Umbraco.Core/Services/UserService.cs
index 659a98ea07..c392011eca 100644
--- a/src/Umbraco.Core/Services/UserService.cs
+++ b/src/Umbraco.Core/Services/UserService.cs
@@ -1338,7 +1338,6 @@ internal partial class UserService : RepositoryService, IUserService
             includedUserGroupAliases = userGroupKeyConversionAttempt.Result.ToArray();
         }
 
-
         if (mergedFilter.NameFilters is not null)
         {
             foreach (var nameFilter in mergedFilter.NameFilters)
@@ -1357,17 +1356,19 @@ internal partial class UserService : RepositoryService, IUserService
         }
         else
         {
-            includeUserStates = new HashSet<UserState>(filter.IncludeUserStates!);
-            includeUserStates.IntersectWith(baseFilter.IncludeUserStates);
+            includeUserStates = new HashSet<UserState>(baseFilter.IncludeUserStates);
+            if (filter.IncludeUserStates is not null && filter.IncludeUserStates.Contains(UserState.All) is false)
+            {
+                includeUserStates.IntersectWith(filter.IncludeUserStates);
+            }
 
             // This means that we've only chosen to include a user state that is not allowed, so we'll return an empty result
-            if(includeUserStates.Count == 0)
+            if (includeUserStates.Count == 0)
             {
                 return Attempt.SucceedWithStatus(UserOperationStatus.Success, new PagedModel<IUser>());
             }
         }
 
-
         PaginationHelper.ConvertSkipTakeToPaging(skip, take, out long pageNumber, out int pageSize);
         Expression<Func<IUser, object?>> orderByExpression = GetOrderByExpression(orderBy);
 
diff --git a/tests/Umbraco.Tests.Integration/CompatibilitySuppressions.xml b/tests/Umbraco.Tests.Integration/CompatibilitySuppressions.xml
index 918b3ea4fe..7cf519f60f 100644
--- a/tests/Umbraco.Tests.Integration/CompatibilitySuppressions.xml
+++ b/tests/Umbraco.Tests.Integration/CompatibilitySuppressions.xml
@@ -78,6 +78,13 @@
     <Right>lib/net9.0/Umbraco.Tests.Integration.dll</Right>
     <IsBaselineSuppression>true</IsBaselineSuppression>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Umbraco.Cms.Tests.Integration.Umbraco.Core.Services.UserServiceCrudTests.Cannot_Request_Disabled_If_Hidden(Umbraco.Cms.Core.Models.Membership.UserState)</Target>
+    <Left>lib/net9.0/Umbraco.Tests.Integration.dll</Left>
+    <Right>lib/net9.0/Umbraco.Tests.Integration.dll</Right>
+    <IsBaselineSuppression>true</IsBaselineSuppression>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Umbraco.Cms.Tests.Integration.Umbraco.Infrastructure.Services.ContentPublishingServiceTests.Publish_Branch_Does_Not_Publish_Unpublished_Children_Unless_Explicitly_Instructed_To(System.Boolean)</Target>
diff --git a/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/UserServiceCrudTests.Filter.cs b/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/UserServiceCrudTests.Filter.cs
index 71b557d4d2..58d79bb2a2 100644
--- a/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/UserServiceCrudTests.Filter.cs
+++ b/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/UserServiceCrudTests.Filter.cs
@@ -1,4 +1,4 @@
-using NUnit.Framework;
+using NUnit.Framework;
 using Umbraco.Cms.Core;
 using Umbraco.Cms.Core.Configuration.Models;
 using Umbraco.Cms.Core.Models;
@@ -10,12 +10,14 @@ namespace Umbraco.Cms.Tests.Integration.Umbraco.Core.Services;
 
 public partial class UserServiceCrudTests
 {
-    [Test]
-    [TestCase(UserState.Disabled)]
-    [TestCase(UserState.All)]
-    public async Task Cannot_Request_Disabled_If_Hidden(UserState includeState)
+    [TestCase(null, 1)]                     // Requesting no filter, will just get the admin user but not the created and disabled one.
+                                            //  - verifies fix for https://github.com/umbraco/Umbraco-CMS/issues/18812
+    [TestCase(UserState.Inactive, 1)]       // Requesting inactive, will just get the admin user but not the created and disabled one.
+    [TestCase(UserState.Disabled, 0)]       // Requesting disabled, won't get any as admin user isn't disabled and, whilst the created one is, disabled users are hidden.
+    [TestCase(UserState.All, 1)]            // Requesting all, will just get the admin user but not the created and disabled one.
+    public async Task Cannot_Request_Disabled_If_Hidden(UserState? includeState, int expectedCount)
     {
-        var userService = CreateUserService(new SecuritySettings {HideDisabledUsersInBackOffice = true});
+        var userService = CreateUserService(new SecuritySettings { HideDisabledUsersInBackOffice = true });
         var editorGroup = await UserGroupService.GetAsync(Constants.Security.EditorGroupKey);
 
         var createModel = new UserCreateModel
@@ -23,21 +25,25 @@ public partial class UserServiceCrudTests
             UserName = "editor@mail.com",
             Email = "editor@mail.com",
             Name = "Editor",
-            UserGroupKeys = new HashSet<Guid> { editorGroup.Key }
+            UserGroupKeys = new HashSet<Guid> { editorGroup.Key },
         };
 
         var createAttempt = await userService.CreateAsync(Constants.Security.SuperUserKey, createModel, true);
         Assert.IsTrue(createAttempt.Success);
 
         var disableStatus =
-            await userService.DisableAsync(Constants.Security.SuperUserKey, new HashSet<Guid>{ createAttempt.Result.CreatedUser!.Key });
+            await userService.DisableAsync(Constants.Security.SuperUserKey, new HashSet<Guid> { createAttempt.Result.CreatedUser!.Key });
         Assert.AreEqual(UserOperationStatus.Success, disableStatus);
 
-        var filter = new UserFilter {IncludeUserStates = new HashSet<UserState> {includeState}};
+        var filter = new UserFilter();
+        if (includeState.HasValue)
+        {
+            filter.IncludeUserStates = new HashSet<UserState> { includeState.Value };
+        }
 
         var filterAttempt = await userService.FilterAsync(Constants.Security.SuperUserKey, filter, 0, 1000);
         Assert.IsTrue(filterAttempt.Success);
-        Assert.AreEqual(0, filterAttempt.Result.Items.Count());
+        Assert.AreEqual(expectedCount, filterAttempt.Result.Items.Count());
     }
 
     [Test]