Try doing it with a FULL tank of gas.
This issue you're seeing is that the gas tank saddle design lends itself to uneven gas levels at below half to quarter tank
And so with sloshing around one side of the tank will hold more fuel than the other when its gets to a lower level.
I went around this myself
and so I remember if I need to make any adjustments to the ride height? it's done on a flat level surface with a full tank of gas.
I hope that makes sense