I definitely recorded with OBS & D3D11 in the past, I think all my HackWeek videos were done with OBS. But yeah I just checked and it doesn’t work for me either. Vulkan does work though 
This might be related to the fact that Studio internally uses ANGLE (an OpenGL emulation layer) to render Qt UI, and that probably picks D3D11 by default and maybe conflicts somehow with 3D view rendering…