X-Pro2 and Manual Lens Question/issue

I have a Rokinon 8mm fisheye lens (my only manual lens). When I mount it on my X-Pro2 it displays different behavior when I look through the EVF and the back of the camera. When I view it on the back of the camera it displays normally but when I look through the electronic viewfinder it displays much darker. And when I increase the aperture on the lens the EVF gets darker just as if it was previewing in manual mode. But the back of the camera doesn't do this. The shutter is in "A"...

X-Pro2 and Manual Lens Question/issue