if i understood it correctly, it was only navier that ate it because soveishu gave it to her and that he wasn't able to eat with her... that he said he ate it too just to have alissa removed... then navier was cured by the benefits of the western's royal bed, and that ergi messed with the test just to have his revenge be successful ┑( ̄Д  ̄)┍
In the novel,after the paternity test and Rashta's trial,and Navier did not face him the night after the trial, Sovieshu became emotionally exhausted. The fact that he was all alone by himself also affected him. So,duke Ergi used this as a method to buy time to escape Sovieshu's wrath and to lure him into finding the baby while ignoring the port. Sovieshu became really pathetic that even marquis Karl pointed to him about the evidences that points he is not the bio father of the baby. Sovieshu did not accept this because he was very guilty of what he did all this time,from Navier to Rashta( if he did not took her as a concubine,he regretted his decision),to abandoning the baby. He thought she's innocent,for me it was like Sovieshu regretted that he took his anger on her than believing he was the father. There's no foul play in the paternity test. Even Navier believed that the baby is not Sovieshu's. And yes,he was sterile because he also ate the cookies with Navier. Navier went therapy,if you remember her first night with Heinley about the Mana bed? In the ss, Sovieshu and Glorym meet again. There was this friend of her with silver hair who everyone thought that she was the missing baby but turned out she's not. Sovieshu also noticed that. When they met Sovieshu offered her the throne,maybe to atone what he did,but she refused. Glorym became Lari's knight commander. And the priest who took the paternity test with the baby got suicide,maybe because he was guilty after what happened to the baby. So it wasn't proven if Glorym is Sovieshu's daughter or not,but she wasn't.
I don't get it. Wasn't the whole plot of the story the fact that it was Sovieshu who was impotent not Navier. Or wait maybe both were impotent but Navier got cured. But why is it that the princess was actually Sovishit's kid