This is what I have learned... If you try to turn and you can feel the wheel go onto one of the edges, lower the pressure little by little until that does not happen. You will thank me if you do as the ride will be so much smoother. This will be dependent on your weight a little. I am 195lbs and for me its pretty much right at 19psi on my Onewheel +. This will allow more of the tire to be in contact with the road as you turn and stop the wobble if its the tire pressure that is causing it.
I made a very quick little illustration of what I mean:
Edit: this is also exaggerated just to make what I am saying clear.. For the normal tire pressure side, your tire is probably under-inflated if this much of the tire is actually touching in a tight turn. You are just trying to avoid the high tire pressure extreme.