Machined size is double

Just finished my second milling machine project and am experiencing a weird issue. When I machine something using one of the canned cycles (wizards) in Mach 3 the machine cuts the exact size I program. When I machine something programmed in Surfcam, the machine cuts the part (circular pocket) twice as big. The code program indicates the correct dimension but the machine cuts it double.
Perplexed in SLC.

Possibly an inch/metric issue? What are the native units set to in Mach3, and is there a G20 or G21 at the start of the code?

Perhaps Surfcam is set at diameter based programming while mach3 is set at radius programming?

I don't know Surfcam, but in my cam program I can set either radius or diameter based programming. I'm pretty sure that mach3 has somethin similar as well.

Wade