diff --git a/idd/LGIdd/CIndirectDeviceContext.cpp b/idd/LGIdd/CIndirectDeviceContext.cpp
index 9a103793..08be3ace 100644
--- a/idd/LGIdd/CIndirectDeviceContext.cpp
+++ b/idd/LGIdd/CIndirectDeviceContext.cpp
@@ -923,13 +923,19 @@ void CIndirectDeviceContext::LGMPTimer()
     ResendCursor();
 }
 
+bool CIndirectDeviceContext::FrameBufferAvailable() const
+{
+  return m_lgmp && m_frameQueue &&
+    lgmpHostQueuePending(m_frameQueue) < LGMP_Q_FRAME_LEN;
+}
+
 CIndirectDeviceContext::PreparedFrameBuffer CIndirectDeviceContext::PrepareFrameBuffer(
   unsigned pitch, const D12FrameFormat& srcFormat, const D12FrameFormat& dstFormat,
   const RECT * dirtyRects, unsigned nbDirtyRects)
 {
   PreparedFrameBuffer result = {};
 
-  if (!m_lgmp || !m_frameQueue)
+  if (!FrameBufferAvailable())
     return result;
 
   if (m_width     != dstFormat.desc.Width  ||
@@ -988,10 +994,6 @@ CIndirectDeviceContext::PreparedFrameBuffer CIndirectDeviceContext::PrepareFrame
 
   KVMFRFrame * fi = m_frame[m_frameIndex];
 
-  // wait until there is room in the queue
-  while (lgmpHostQueuePending(m_frameQueue) == LGMP_Q_FRAME_LEN)
-    Sleep(0);
-
   if (dstFormat.format == FRAME_TYPE_INVALID)
   {
     DEBUG_ERROR("Unsupported frame format, skipping frame");
diff --git a/idd/LGIdd/CIndirectDeviceContext.h b/idd/LGIdd/CIndirectDeviceContext.h
index 69f5ab51..c348ed33 100644
--- a/idd/LGIdd/CIndirectDeviceContext.h
+++ b/idd/LGIdd/CIndirectDeviceContext.h
@@ -210,6 +210,7 @@ public:
     uint8_t* mem;
   };
 
+  bool FrameBufferAvailable() const;
   PreparedFrameBuffer PrepareFrameBuffer(unsigned pitch, const D12FrameFormat& srcFormat, const D12FrameFormat& dstFormat, const RECT * dirtyRects, unsigned nbDirtyRects);
   bool PublishFrameBuffer(unsigned frameIndex);
   void WriteFrameBuffer(unsigned frameIndex, void* src, size_t offset, size_t len, bool setWritePos) const;
diff --git a/idd/LGIdd/CSwapChainProcessor.cpp b/idd/LGIdd/CSwapChainProcessor.cpp
index 3090d4dc..068d0f30 100644
--- a/idd/LGIdd/CSwapChainProcessor.cpp
+++ b/idd/LGIdd/CSwapChainProcessor.cpp
@@ -226,18 +226,18 @@ bool CSwapChainProcessor::SwapChainThreadCore()
         lastFrameNumber = frameNumber;
         if (!SwapChainNewFrame(surface, dirtyRectCount, colorSpace, sdrWhiteLevel))
           DEBUG_WARN("Failed to submit frame");
+      }
 
-        // report that all GPU processing for this frame has been queued
-        hr = IddCxSwapChainFinishedProcessingFrame(m_hSwapChain);
-        if (FAILED(hr))
-        {
-          // A lost path is normal (mode change/topology rebuild); Windows
-          // reassigns a fresh swap chain. Just exit and let it.
-          if (hr != STATUS_GRAPHICS_PATH_NOT_IN_TOPOLOGY)
-            DEBUG_ERROR_HR(hr, "IddCxSwapChainFinishedProcessingFrame Failed");
-          break;
-        }
-
+      // Every acquired frame must be finished before the next acquire, even if
+      // its presentation number was a duplicate and no work was submitted.
+      hr = IddCxSwapChainFinishedProcessingFrame(m_hSwapChain);
+      if (FAILED(hr))
+      {
+        // A lost path is normal (mode change/topology rebuild); Windows
+        // reassigns a fresh swap chain. Just exit and let it.
+        if (hr != STATUS_GRAPHICS_PATH_NOT_IN_TOPOLOGY)
+          DEBUG_ERROR_HR(hr, "IddCxSwapChainFinishedProcessingFrame Failed");
+        break;
       }
     }
     else
@@ -339,6 +339,11 @@ static FrameType GetFrameType(DXGI_FORMAT format)
 bool CSwapChainProcessor::SwapChainNewFrame(ComPtr<IDXGIResource> acquiredBuffer, unsigned dirtyRectCount,
   DXGI_COLOR_SPACE_TYPE colorSpace, UINT sdrWhiteLevel)
 {
+  // Never hold an IddCx frame waiting for a slow or disconnected client. In
+  // particular, monitor departure cannot complete until the frame is released.
+  if (!m_devContext->FrameBufferAvailable())
+    return true;
+
   ComPtr<ID3D11Texture2D> texture;
   HRESULT hr = acquiredBuffer.As(&texture);
   if (FAILED(hr))
@@ -532,8 +537,10 @@ bool CSwapChainProcessor::SwapChainNewFrame(ComPtr<IDXGIResource> acquiredBuffer
     frameDirtyRects,
     frameDirtyRectCount);
 
+  // The LGMP timer can fill the queue with a subscriber resend after the early
+  // availability check. Treat this as a dropped frame rather than an error.
   if (!buffer.mem)
-    return false;
+    return true;
 
   CFrameBufferResource * fbRes = m_fbPool.Get(buffer,
     (size_t)layout.Footprint.RowPitch * dstFormat.desc.Height);