Vermeer bale shape

So used my new to me rancher 665 a few times now. And i am still not sure how exactly the bale shape on the monitoris spose to work. As the baler fills are both spose to rise to nearly the top? Also I question if my sensors are reading accuratly seems like the left(drivers side) reads higher than it should. Infact if weaving by looking and bale shape on the monitor it will make a poor lopsided bale. If i just weave back and forth evenly I have much better success. So first question how is thebale shape bars suppose to operate. And second what is the proper way to verify calibration/operation of the bale shape sensors.

Vermeer bale shape