Generating font files from Multiple Master file

I’m trying to generate font files from a font that has two masters, a light and a bold. Glyphs generates two separate files with the right names, but both files have only the light glyphs. So Glyphs generates the light file two times and gives the different names.

What am I doing wrong ?

Thanks for helping

Did you set the interpolation values? Please see the manual from page 18.

Aha right, that was missing.