Hi, need some help getting a concave face rad to come into size, using IGF function and just regular G03 L function I have a radius that won't come up to size coming up small by around .005. depth is within .0004, start dia is within .0005

Radius has a tolerance of 1.250+/- .0005 and is consistently .005 undersize at 1.245R

I'm running a 55 degree diamond (left hand) .008R horizontally, Rad is 1.25R X.135 dp with a start on dia of 1.111

Tool is around .0005 below center.

Never had this issue before and any help/thoughts are appreciated.