Streaks on door
And remember, semi-gloss takes 30 days or so to cure. You may see what look like inconsistencies between coats in places that will mellow over time.
If it is about paint runs? Proceed as suggested.
If you are seeing color streaks it may be the pigment is not mixed completely in the paint can. You cannot rely only on the shaker at the paint store. You have to stir the paint when you get it home as well. And stir it before each use and even during use if it is a heavily pigmented color.