Having difficulty installing Grado cartridge on a Rega turntable


I'm trying to install a new Grado Sonata 2 cartridge on my Rega RP3 turntable. I'm replacing the Grado Sonata 1 cartridge which was installed by the dealer who is now inaccessible. I understand Rega and Grado are somewhat incompatible. I'm having all sorts of problems installing the new cartridge and need help. It doesn't behave like the old one.
Does anyone know of a Rega service person in the Long Island, New York area?
128x128rvpiano

After checking proper angle, anti-skating, proper stylus pressure and leveling the surface on which the turntable is standing, an oddity occurs.
At the end of a record the tonearm shoots toward the middle of the disc and sometimes on to the label.
Also, there is evidence of mistracking
Make sure the arm isn't hitting something in its travels, binding on something....sure sounds mechanical to me.
I found the problem

The stylus is bent off center.  I'll have to return it.

Thank you for all your replies.

Rega arms and grado  cartridges are not incompatible. I'm not sure where you heard that one.

But whatever you have going on is something totally diferent.