nut replacement

Hello All, I am very close to pulling the trigger on a PRS Silver Sky John Mayer Signature. One upgrade I'm already planning on making, is switching out the factory nut with a brass one (Jerry Garcia had brass nuts on most if not all of his guitars) . I did this to my Mexican Strat and I...

Like the title reveals I had my axe plek’d and the nut replaced. The guitar won’t intonate on all strings. I already changed strings. Didn’t help. Current stings are NYXL 10-46. Pick ups are at a reasonable height at 5/64th and 6/64th respectively. The weird thing is the 12th fret harmonics are...