diff --git a/src/AcDream.App/Rendering/GameWindow.cs b/src/AcDream.App/Rendering/GameWindow.cs
index 5baab269..d55788e3 100644
--- a/src/AcDream.App/Rendering/GameWindow.cs
+++ b/src/AcDream.App/Rendering/GameWindow.cs
@@ -1625,7 +1625,12 @@ public sealed class GameWindow :
     /// previously off the new viewport snap back to default positions.
     /// </summary>
     private void OnFramebufferResize(Silk.NET.Maths.Vector2D<int> newSize)
-        => _framebufferResize.Resize(newSize);
+    {
+        // #387 evidence line (permanent — resize events are rare and this is
+        // the only trace of whether the native event fired at all).
+        Console.WriteLine($"window: framebuffer resize event {newSize.X}x{newSize.Y}");
+        _framebufferResize.Resize(newSize);
+    }
 
     private void OnClosing() => CompleteShutdown(releaseNativeWindow: false);
 
diff --git a/src/AcDream.App/Rendering/Gpu/Vk/VulkanGraphicsContext.cs b/src/AcDream.App/Rendering/Gpu/Vk/VulkanGraphicsContext.cs
index 0441ada8..cedef45b 100644
--- a/src/AcDream.App/Rendering/Gpu/Vk/VulkanGraphicsContext.cs
+++ b/src/AcDream.App/Rendering/Gpu/Vk/VulkanGraphicsContext.cs
@@ -409,12 +409,17 @@ internal sealed unsafe class VulkanGraphicsContext : IDisposable
         if (VulkanSwapchainRecreationPolicy.OnFramebufferSize(width, height)
             == VulkanSwapchainAction.Idle)
         {
+            // No log here: while minimised this runs at frame rate.
             return false;
         }
 
         VulkanInterop.Check(_vk!.DeviceWaitIdle(_device), "vkDeviceWaitIdle (recreate)");
         _recreateAtFrameBoundary = false;
-        return _swapchain!.Recreate(_pacing, width, height);
+        bool recreated = _swapchain!.Recreate(_pacing, width, height);
+        // #387 evidence line (permanent): the ONLY trace of the swapchain
+        // extent actually changing after startup.
+        _log($"vulkan: swapchain recreated {width}x{height} ok={recreated}");
+        return recreated;
     }
 
     /// <summary>
diff --git a/src/AcDream.App/Settings/RuntimeSettingsTargets.cs b/src/AcDream.App/Settings/RuntimeSettingsTargets.cs
index 91fc945b..e1729a07 100644
--- a/src/AcDream.App/Settings/RuntimeSettingsTargets.cs
+++ b/src/AcDream.App/Settings/RuntimeSettingsTargets.cs
@@ -60,6 +60,10 @@ internal sealed class SilkRuntimeDisplayWindowTarget : IRuntimeDisplayWindowTarg
             TryParseResolution(display.Resolution, out int width, out int height);
         if (haveResolution && (_window.Size.X != width || _window.Size.Y != height))
         {
+            // #387 evidence line (permanent): the resolution-pick write path.
+            Console.WriteLine(
+                $"display: resolution pick {width}x{height} " +
+                $"(window was {_window.Size.X}x{_window.Size.Y})");
             _window.Size = new Vector2D<int>(width, height);
         }