diff --git a/idd/LGIdd/CIndirectDeviceContext.cpp b/idd/LGIdd/CIndirectDeviceContext.cpp
index 7e0dc0ae..de4b68c8 100644
--- a/idd/LGIdd/CIndirectDeviceContext.cpp
+++ b/idd/LGIdd/CIndirectDeviceContext.cpp
@@ -635,6 +635,39 @@ void CIndirectDeviceContext::ReplugMonitor()
     m_finishInitQueued.store(1);
 }
 
+void CIndirectDeviceContext::ReloadSettings()
+{
+  bool modesLoaded = false;
+
+  AcquireSRWLockExclusive(&m_modeReloadLock);
+
+  CSettings::DisplayMode extraMode;
+  if (g_settings.GetExtraMode(extraMode))
+  {
+    const unsigned refresh = g_settings.GetDefaultRefresh();
+    if (extraMode.refresh != refresh)
+    {
+      extraMode.refresh = refresh;
+      if (!g_settings.SetExtraMode(extraMode))
+      {
+        ReleaseSRWLockExclusive(&m_modeReloadLock);
+        return;
+      }
+    }
+  }
+
+  modesLoaded = PopulateDefaultModes();
+  ReleaseSRWLockExclusive(&m_modeReloadLock);
+
+  if (!modesLoaded)
+  {
+    DEBUG_ERROR("Failed to reload the display mode list");
+    return;
+  }
+
+  ReplugMonitor();
+}
+
 void CIndirectDeviceContext::OnMonitorDestroyed(IDDCX_MONITOR monitor)
 {
   AcquireSRWLockExclusive(&m_stateLock);
@@ -936,19 +969,23 @@ void CIndirectDeviceContext::SetResolution(uint32_t width, uint32_t height)
   mode.refresh   = g_settings.GetDefaultRefresh();
   mode.preferred = true;
 
-  AcquireSRWLockExclusive(&m_stateLock);
-  m_setMode   = mode;
-  m_doSetMode = true;
-  ReleaseSRWLockExclusive(&m_stateLock);
+  bool modesLoaded = false;
+  AcquireSRWLockExclusive(&m_modeReloadLock);
+  if (g_settings.SetExtraMode(mode))
+    modesLoaded = PopulateDefaultModes();
+  ReleaseSRWLockExclusive(&m_modeReloadLock);
 
-  g_settings.SetExtraMode(mode);
-
-  if (!PopulateDefaultModes())
+  if (!modesLoaded)
   {
     DEBUG_ERROR("Failed to rebuild the display mode list");
     return;
   }
 
+  AcquireSRWLockExclusive(&m_stateLock);
+  m_setMode   = mode;
+  m_doSetMode = true;
+  ReleaseSRWLockExclusive(&m_stateLock);
+
   // IddCxMonitorUpdateModes[2] does not invalidate Windows' cached mode list,
   // so the only reliable way to apply a new mode is to depart and re-arrive the
   // monitor, forcing Windows to rebuild the topology from the new mode list.
diff --git a/idd/LGIdd/CIndirectDeviceContext.h b/idd/LGIdd/CIndirectDeviceContext.h
index 358ba8dd..9dbaae1b 100644
--- a/idd/LGIdd/CIndirectDeviceContext.h
+++ b/idd/LGIdd/CIndirectDeviceContext.h
@@ -215,6 +215,11 @@ private:
   // Never held across an IddCx API call - snapshot then call.
   mutable SRWLOCK m_modeLock = SRWLOCK_INIT;
 
+  // Serializes registry-backed mode changes with rebuilding m_displayModes.
+  // Reload requests arrive on the pipe thread while dynamic resolution
+  // requests arrive on the LGMP timer thread.
+  SRWLOCK m_modeReloadLock = SRWLOCK_INIT;
+
   CSettings::DisplayModes m_displayModes;
   CEdid                   m_edid;
 
@@ -238,6 +243,7 @@ public:
   void InitAdapter();
   void FinishAdapterInit(UINT connectorIndex);
   void FinishInit(UINT connectorIndex);
+  void ReloadSettings();
   void ReplugMonitor();
 
   void OnMonitorDestroyed(IDDCX_MONITOR monitor);
diff --git a/idd/LGIdd/CPipeServer.cpp b/idd/LGIdd/CPipeServer.cpp
index 24fab90b..cee504aa 100644
--- a/idd/LGIdd/CPipeServer.cpp
+++ b/idd/LGIdd/CPipeServer.cpp
@@ -262,7 +262,7 @@ void CPipeServer::HandleReloadSettings()
 
   AcquireSRWLockShared(&m_deviceContextLock);
   if (m_deviceContext)
-    m_deviceContext->ReplugMonitor();
+    m_deviceContext->ReloadSettings();
   ReleaseSRWLockShared(&m_deviceContextLock);
 }
 
diff --git a/idd/LGIdd/CSettings.cpp b/idd/LGIdd/CSettings.cpp
index ae3bd03c..4bab5d8c 100644
--- a/idd/LGIdd/CSettings.cpp
+++ b/idd/LGIdd/CSettings.cpp
@@ -76,7 +76,7 @@ CSettings::DisplayModes CSettings::LoadModes()
   return displayModes;
 }
 
-void CSettings::SetExtraMode(const DisplayMode& mode)
+bool CSettings::SetExtraMode(const DisplayMode& mode)
 {
   WCHAR buf[64];
   _snwprintf_s(buf, _countof(buf), _TRUNCATE, L"%ux%u@%u%s",
@@ -94,15 +94,24 @@ void CSettings::SetExtraMode(const DisplayMode& mode)
 
   if (ec != ERROR_SUCCESS)
   {
-    DEBUG_INFO("Failed to write key");
-    return;
+    DEBUG_ERROR_HR(ec, "Failed to open settings key for ExtraMode");
+    return false;
   }
 
   const WCHAR* valueName = L"ExtraMode";
   const DWORD  cb = (DWORD)((wcslen(buf) + 1) * sizeof(WCHAR));
 
-  RegSetValueExW(hKey, valueName, 0, REG_SZ, (const BYTE*)buf, cb);
+  ec = RegSetValueExW(hKey, valueName, 0, REG_SZ,
+    (const BYTE*)buf, cb);
   RegCloseKey(hKey);
+
+  if (ec != ERROR_SUCCESS)
+  {
+    DEBUG_ERROR_HR(ec, "Failed to write ExtraMode");
+    return false;
+  }
+
+  return true;
 }
 
 std::wstring CSettings::ReadStringValue(const wchar_t* name, const wchar_t* defaultValue)
diff --git a/idd/LGIdd/CSettings.h b/idd/LGIdd/CSettings.h
index f31a763e..7b932557 100644
--- a/idd/LGIdd/CSettings.h
+++ b/idd/LGIdd/CSettings.h
@@ -39,7 +39,7 @@ class CSettings
     CSettings();
 
     DisplayModes LoadModes();
-    void SetExtraMode(const DisplayMode & mode);
+    bool SetExtraMode(const DisplayMode & mode);
     bool GetExtraMode(DisplayMode & mode);
     unsigned GetDefaultRefresh() const;