You mean there's more than one position?Have you tried pushing the meyer mouthpiece in a bit, and pulling the jody jazz out a bit? If the tone is consistently flat or sharp through the full range of the horn, it may be as simple as not having the mouthpiece correctly positioned on the neck.
Bandmommy knows all things and should be obeyed.Swap mouthpieces. Is the Selmer still flat and the Yanagisawa still sharp?
If so you need to push the mouthpiece in on the Selmer, and pull out on the Yana.
It's only a matter of using your logical brain cell.
But what if the Selmer is a tenor and the Yana is an alto?Bandmommy knows all things and should be obeyed.
Unless the Selmer is an alto and the Yanagisawa a tenor.