please show the screenshot of the setup. Rather checks yourself how you enter numbers. A common mistake is forgetting to click "intrinsic"(i.e. Magnetization from H), or mistaking units.
Intrinsic is when your guess hte magnetization yourself. External is for feeding the measured data. The difference is just the field H added to M (Bex=mo(M+H) , Bin=moM - a virtual quantity in measurements, or just 4piM in Gaussian, which has a natural meaning of normalized magnetization). So feed it in Gaussian for avoiding conversion mistakes.
(ok. I myself often make mistakes when converting back and forth, correct me if I did it here)