Thank you!
Well, comparing your second image (the close-up) with two of my bikes it really looks odd.
The upmost part of the seat tube seems to be a bit higher on yours.
Also there is a small gap between the plastic part and the steering tube - I don’t have that gap, both parts seem to touch (looking from the side).
The ball’s shaft has to be completely straight and it should be in a 90° angle to the seat tube.
Even if do believe that the chance for an upwards bent shaft is much bigger - I still think that on your bike, the ball’s shaft must be bent downwards.
(The downward bent shaft “shortens” the rear tube, therefore the rear wheel sits “higher”.)
There is nothing to adjust btw.
Please try to check above.
HInt: If the ball was overstressed, there can occur cracks in the frame, around the shaft’s thread.
Please look for cracks, too.