Same thing happened to mine when I first got it. Bob Graham said sometimes shipping has cuased a slight slippage of parts. he said
" Raise the arm up it's highest point, then slightly loosen the three screws underneath the VTA adjusting tower (this will be on the bottom of the mounting base, so you need to remove the arm from the turntable. While the arm is in the upward position, gently re-tighten the three screws. If this doesn't fix it, try the same thing, but with the arm at the lowest position."
This worked for me and I have had no further problems.
Otherwise you will probably have to return it to Graham.
let is know if this works
" Raise the arm up it's highest point, then slightly loosen the three screws underneath the VTA adjusting tower (this will be on the bottom of the mounting base, so you need to remove the arm from the turntable. While the arm is in the upward position, gently re-tighten the three screws. If this doesn't fix it, try the same thing, but with the arm at the lowest position."
This worked for me and I have had no further problems.
Otherwise you will probably have to return it to Graham.
let is know if this works