Cosmo Star System problem

[You must be registered and logged in to see this image.] So as we can see, I have my lovely system here, but for some reason, I can't add any Main Order stars to the yellow slot, despite having four available. Whenever I try, it just says "Similar outbreaks injected into star soul attributes, failed".

Plz halp :(

Apparently if they have the same stats, you can't use them. Not talking about the stats written in purple. But the stuff written in white, under the big LV1/LV2.