I have a 16 F150 and Mine too came out 1/8" lower than unladen, and I found I have sway above 65 MPH. It think it may be a bit too much weight transfer on mine since not only does it transfer weight forward, but back to the trailer, and in my case made the ball too light. Going to pull a shim and tilt the head up a bit to relieve some pressure on the springs. Dropping a link will make it too light in the front.
In the OP's case, need to verify how much weight is still on the ball. It may be perfectly fine.