well the poolish couple next door have both daughters as British,
and I attested bofe ( signed a form saying the parents were good eggs which they are)
so there is something wrong with the story. I am not sure how EU nationals can now be illegals, but they have managed it. That would be a bar.
Both my parents werent born in dear old blighty and no one has questioned my nationality ( but I kinda look nordic see)
They should see an immigration lawyer ( = moolah, and AB is cheap) but the hurdle ( ha pun intended) is that a decision has been made and has to be over-turned father than an application prepared and submitted