some genes lost in OrthoGroup when running orthofinder with additional species

[leon945945]

Hi, I want to get the orthologs of one certain gene (anchor gene) with orthofinder, then I ran orthofinder with the proteins of some species, however when I reran orthofinder with additional species, some genes appeared before didn't exist in the OrthoGroup that anchor gene was in. I am confused with it, what makes it happen? Thank you.