This is the same as using leftover baked potatoes and the only way to do hash browns IMHO.
First problem: you’re doing it with raw potatoes. Start with leftover bakers. all the liquid is out so all you have to do is warm them up and let them get crispy.
Second problem: oil. yuck. Please, for your own sake use butter and use more than “a little.” Of course, too much can make them greasy, but you want a decent amount to get that lovely flavor and a crispy texture.
and yes! Leave them alone!
It’s okay, guys. I’m an expert on hashbrowns; I used to work at Denny’s. Every Sunday morning around 7 we would unload about 10 pounds of hashbrowns onto the grill and left them cook there all the live long day. By about noon, they would be solid hunks of brown char. So, basically, what I’m saying is, you need to cook them anywhere from 0 to 5 hours to really get the full experience.