There is an issue I am having with dev mode for a while now. The randoms texts that appears on screen while dev mode is on doesnt appear at all, even when you type something that usually gives a feedback like "where" which prints locations on the screen won't work. I wonder what's causing this
Have you changed the resolution of Oni? If so, try going back to 1024x768 and see if that fixes it. I heard that at higher resolutions the console line disappears.