Iporting AFM strange behavior

I notice a strange behavior by importing AFM file to Glpyhs in a file with existing kerning groups.
Instead of importing the complete AFM values as exceptions (wich I later can compress), Glyphs seams to compress the kerning during the import.
I could not figure out exact wich kerning value is taken from the AFM. For example kerning pair /n/o it does not take the /n/o kerning value fron the AFM, or any other member of the “o” group. Glyphs seems to calculate a new kerning value.
@GeorgSeifert, could you please advice on this?

Can you send me the files you use?

Hi! Many thanks for the quick respond!! I just send you the files per email.