TooTall the scoop that comes with the aeropress is a 12gr scoop. If you use one and a half you are using exactly what I am suggesting – 18gr, that is well over two times as much coffee as you would use on an espresso maker. Even the maker recommends two scoops – 24-26gr for a 10 ounce mug.
Other than that I do nothing different than you, and I do have non sealing issues as well as the water coming only through the centre on my old aeropress while coming through the entire filter on my new one, so the curve in the middle is making a difference. Maybe my first Aeropress was a tad defective, I don’t know, see how well the second one will do.