In real F-5 landings, the plane is kept on rear wheels for a while for aero-braking. In DCS, no matter how soft you land, how fast or how slow you land, after the main gear touches, the nose wheel "wants to" reach to ground immediately. I am not sure about the FM, but this needs a fix.
Currently after the touchdown you need to add some pitch with your stick to keep the nose up, and usually this leads to small oscillation.