[udobroemme]

Now I understand what you meant. I never touched the rendering method setting before. It always stayed at "auto". Now I made some tests with both of your versions.

Kodi 18.9: "msdk mvc (SW)". It works with all rendering methods (DXVA, Pixel Shaders, Software) and gives a stereoscopic image.
Kodi 19.1, hw mvc decoder support level=19: "msdk mvc (SW)". DXVA gives a black screen, Pixel Shaders and SW rendering methods give a monoscopic image.
Kodi 19.1, hw mvc decoder support level=20: "ff-h264-d3d11va (HW)". All render methods show a monoscopic image. Imho this is correct because no hardware decoding is supported on my machine.