CreateSwapChainForHwnd returns E_ACCESSDENIED

[RLinc]

Hello,

Thank you for the Intel Media SDK samples and Tutorials, the coding is very good.

I have an issue with the provided class d3d11_device.cpp, I have spent a couple of days trying to debug and have now surrendered.
It is the continuation of an existing error found on the Intel forum:
https://software.intel.com/en-us/forums/intel-media-sdk/topic/562554

First call into a new class succeeds, second call into a NEW class fails using the same HWND.

However, I'm unable to create a new window handle as a work around (CCTV switching in a single HWND).
The error is 'CreateSwapChainForHwnd returns E_ACCESSDENIED' on a second Class and Call using the same window handle.
A believe a DirectX resource / object has not been properly freed.

I believe the issue to be related to the following thread:
https://stackoverflow.com/questions/20556885/directx-11-createswapchainforhwnd-fails-with-e-accessdenied

And have subsequently called both:
D3D11Context->ClearState();
D3D11Context->Flush();

in the Close() function as recommended by Microsoft to no affect, similar to the stackoverflow thread above.

Next I tried the 'Graphics Debugging' console tool in Visual Studio to see what, if any objects are left open agianst the HWND.
However when debugging using the 'Graphics Debugging' tool, it does not like the assignments:
    
    m_pDXGIDev = m_pD3D11Device;
    m_pDX11VideoDevice = m_pD3D11Device; <<--
    m_pVideoContext = m_pD3D11Ctx;       <<--
    
Do you have any pointers, it would be greatly appreciated, Cheers.