It was reported that the D850 has focus issues with the outer focus points but not with the center point.
I can confirm I have this issue with the 50mm. Using the viewfinder the center point is focused and sharp at 1.4 but the outer focus points are soft and out of focus. Using Live view this is not an issue.
It was suggested to update the firmware on the lens. I updated the dock`s firmware then mounted the lens. However the sigma software says that my lens is updated with FW 1.00 but sigma's site says the latest is 1.01. Can you guys check yours? I'm on mac so if i have to borrow a windows computer to update the firmware I will go that route.