When preferences > settings > selection is set to "Select faces with: Center" (which is mandatory for orthographic modeling), the actual face selected is not highlighted.
It is selected, but only the face is highlighted, not the face center icon. This must be a visual bug or oversight... it makes modeling in an ortho viewport very confusing, and differs from Legacy Maya modeling.
I'm finding a few bugs like this as I get into Maya modeling, if there's a better place I should be reporting them please let me know.
