connect camera with UE4, the image is upside down

I’m trying connect the camera with UE4 on my win10, somehow the image was flipped, it’s upside down!
my camera is canon mark 3, it can send normal live image to windows;
I add a MediaPlayer in my project, wanna connect a virtual camera with real camera. however the image is like that.

did you get this to work? I’m having the same issue with an eos-1d

Found if you set DefaultGraphicsRHI to DX12 the image is flipped but if it uses DX11 it is ok.