I think Iscah has the right of it - it's the obscenity filter not seeing the space between the names and detecting a resulting name of a well-known male impotency medication and thus blocking your name choice accordingly (it might seem a bit pendantic, but that's obscenity filters for you).

So basically your desired name has unfortunately become a victim of the 'Scunthorpe Problem' where a seemingly innocent name or word.... turns out to feature within it's letters something else (as people often use this very trick to actually beat obscenity filters, it's why they're so strict about this).

Unfortunately there isn't anything you can really do except try another name.