diff --git a/src/WayfarerMobile.Core/Interfaces/IGroupsService.cs b/src/WayfarerMobile.Core/Interfaces/IGroupsService.cs
index 716619d..0ee7339 100644
--- a/src/WayfarerMobile.Core/Interfaces/IGroupsService.cs
+++ b/src/WayfarerMobile.Core/Interfaces/IGroupsService.cs
@@ -49,7 +49,7 @@ Task<Dictionary<string, MemberLocation>> GetLatestLocationsAsync(
 
     /// <summary>
     /// Updates the current user's peer visibility setting.
-    /// PATCH /api/mobile/groups/{groupId}/peer-visibility
+    /// POST /api/mobile/groups/{groupId}/peer-visibility
     /// </summary>
     /// <param name="groupId">The group ID.</param>
     /// <param name="disabled">Whether peer visibility should be disabled.</param>
diff --git a/src/WayfarerMobile.Core/Models/GroupLocationModels.cs b/src/WayfarerMobile.Core/Models/GroupLocationModels.cs
index d691684..2e91eec 100644
--- a/src/WayfarerMobile.Core/Models/GroupLocationModels.cs
+++ b/src/WayfarerMobile.Core/Models/GroupLocationModels.cs
@@ -135,7 +135,7 @@ public class GroupLocationResult
 
 /// <summary>
 /// Request to update peer visibility.
-/// PATCH /api/mobile/groups/{groupId}/peer-visibility
+/// POST /api/mobile/groups/{groupId}/peer-visibility
 /// </summary>
 public class PeerVisibilityUpdateRequest
 {
diff --git a/src/WayfarerMobile/Services/GroupsService.cs b/src/WayfarerMobile/Services/GroupsService.cs
index d8a71ee..162fb26 100644
--- a/src/WayfarerMobile/Services/GroupsService.cs
+++ b/src/WayfarerMobile/Services/GroupsService.cs
@@ -287,7 +287,7 @@ public async Task<bool> UpdatePeerVisibilityAsync(
 
         try
         {
-            var request = CreateRequest(new HttpMethod("PATCH"), $"/api/mobile/groups/{groupId}/peer-visibility");
+            var request = CreateRequest(HttpMethod.Post, $"/api/mobile/groups/{groupId}/peer-visibility");
             request.Content = JsonContent.Create(new PeerVisibilityUpdateRequest { Disabled = disabled }, options: JsonOptions);
 
             var response = await HttpClientInstance.SendAsync(request, cancellationToken);
diff --git a/tests/WayfarerMobile.Tests/Unit/Services/ProductionGroupsServiceTests.cs b/tests/WayfarerMobile.Tests/Unit/Services/ProductionGroupsServiceTests.cs
new file mode 100644
index 0000000..474bd3c
--- /dev/null
+++ b/tests/WayfarerMobile.Tests/Unit/Services/ProductionGroupsServiceTests.cs
@@ -0,0 +1,110 @@
+using System.Net;
+using System.Text.Json;
+using Microsoft.Extensions.Logging;
+using Moq.Protected;
+using WayfarerMobile.Services;
+
+namespace WayfarerMobile.Tests.Unit.Services;
+
+/// <summary>
+/// Regression tests for the production <see cref="GroupsService"/> peer-visibility request.
+/// </summary>
+public class ProductionGroupsServiceTests
+{
+    [Theory]
+    [InlineData(true, HttpStatusCode.OK, true)]
+    [InlineData(false, HttpStatusCode.Forbidden, false)]
+    public async Task UpdatePeerVisibilityAsync_SendsOneAuthenticatedPostAndReturnsStatusResult(
+        bool disabled,
+        HttpStatusCode statusCode,
+        bool expectedResult)
+    {
+        var groupId = Guid.Parse("11111111-2222-3333-4444-555555555555");
+        HttpMethod? capturedMethod = null;
+        Uri? capturedUri = null;
+        string? capturedAuthorization = null;
+        string? capturedContent = null;
+        var contactCount = 0;
+        var handler = new Mock<HttpMessageHandler>();
+        handler
+            .Protected()
+            .Setup<Task<HttpResponseMessage>>(
+                "SendAsync",
+                ItExpr.IsAny<HttpRequestMessage>(),
+                ItExpr.IsAny<CancellationToken>())
+            .Returns<HttpRequestMessage, CancellationToken>(async (request, token) =>
+            {
+                contactCount++;
+                capturedMethod = request.Method;
+                capturedUri = request.RequestUri;
+                capturedAuthorization = request.Headers.Authorization?.ToString();
+                capturedContent = await request.Content!.ReadAsStringAsync(token);
+
+                return new HttpResponseMessage(statusCode);
+            });
+
+        using var httpClient = new HttpClient(handler.Object);
+        var httpClientFactory = new Mock<IHttpClientFactory>();
+        httpClientFactory.Setup(factory => factory.CreateClient("WayfarerApi")).Returns(httpClient);
+        var settings = new Mock<ISettingsService>();
+        settings.Setup(value => value.IsConfigured).Returns(true);
+        settings.Setup(value => value.ServerUrl).Returns("https://api.example.com");
+        settings.Setup(value => value.ApiToken).Returns("test-token-123");
+        var service = new GroupsService(
+            settings.Object,
+            Mock.Of<ILogger<GroupsService>>(),
+            httpClientFactory.Object);
+
+        var result = await service.UpdatePeerVisibilityAsync(groupId, disabled);
+
+        result.Should().Be(expectedResult);
+        contactCount.Should().Be(1);
+        capturedMethod.Should().Be(HttpMethod.Post);
+        capturedUri.Should().Be(new Uri($"https://api.example.com/api/mobile/groups/{groupId}/peer-visibility"));
+        capturedAuthorization.Should().Be("Bearer test-token-123");
+        using var content = JsonDocument.Parse(capturedContent!);
+        content.RootElement.GetProperty("disabled").GetBoolean().Should().Be(disabled);
+    }
+
+    [Fact]
+    public async Task UpdatePeerVisibilityAsync_ForwardsCancellationToSendAsync()
+    {
+        var sendStarted = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
+        var sendCompletion = new TaskCompletionSource<HttpResponseMessage>(
+            TaskCreationOptions.RunContinuationsAsynchronously);
+        var capturedCancellationToken = CancellationToken.None;
+        var handler = new Mock<HttpMessageHandler>();
+        handler
+            .Protected()
+            .Setup<Task<HttpResponseMessage>>(
+                "SendAsync",
+                ItExpr.IsAny<HttpRequestMessage>(),
+                ItExpr.IsAny<CancellationToken>())
+            .Returns<HttpRequestMessage, CancellationToken>((_, token) =>
+            {
+                capturedCancellationToken = token;
+                sendStarted.SetResult();
+                return sendCompletion.Task;
+            });
+
+        using var httpClient = new HttpClient(handler.Object);
+        var httpClientFactory = new Mock<IHttpClientFactory>();
+        httpClientFactory.Setup(factory => factory.CreateClient("WayfarerApi")).Returns(httpClient);
+        var settings = new Mock<ISettingsService>();
+        settings.Setup(value => value.IsConfigured).Returns(true);
+        settings.Setup(value => value.ServerUrl).Returns("https://api.example.com");
+        var service = new GroupsService(
+            settings.Object,
+            Mock.Of<ILogger<GroupsService>>(),
+            httpClientFactory.Object);
+        using var cancellationSource = new CancellationTokenSource();
+
+        var resultTask = service.UpdatePeerVisibilityAsync(Guid.NewGuid(), disabled: true, cancellationSource.Token);
+        await sendStarted.Task;
+        cancellationSource.Cancel();
+
+        capturedCancellationToken.IsCancellationRequested.Should().BeTrue();
+        sendCompletion.SetCanceled(capturedCancellationToken);
+        (await resultTask).Should().BeFalse();
+    }
+}
diff --git a/tests/WayfarerMobile.Tests/WayfarerMobile.Tests.csproj b/tests/WayfarerMobile.Tests/WayfarerMobile.Tests.csproj
index 2629738..cb7fef8 100644
--- a/tests/WayfarerMobile.Tests/WayfarerMobile.Tests.csproj
+++ b/tests/WayfarerMobile.Tests/WayfarerMobile.Tests.csproj
@@ -25,6 +25,7 @@
     <Compile Include="..\..\src\WayfarerMobile\Data\Repositories\SegmentRepository.cs" Link="Production\SegmentRepository.cs" />
     <Compile Include="..\..\src\WayfarerMobile\Interfaces\ITripContentService.cs" Link="Production\ITripContentService.cs" />
     <Compile Include="..\..\src\WayfarerMobile\Interfaces\ITripMetadataBuilder.cs" Link="Production\ITripMetadataBuilder.cs" />
+    <Compile Include="..\..\src\WayfarerMobile\Services\GroupsService.cs" Link="Production\GroupsService.cs" />
     <Compile Include="..\..\src\WayfarerMobile\Services\TripContentService.cs" Link="Production\TripContentService.cs" />
     <!-- Test Framework -->
     <PackageReference Include="Microsoft.Extensions.Http" Version="10.0.11" />