Once a last name gets transcribed and entered in your genealogical database, it can become official even when it might not be.
For some people, we may only have one written reference to their name–perhaps on a death certificate for a child. We transcribe that name and enter it in our database only to discover that we can find no reference to that person. Time marches on and we go to other ancestors.
Years later when we revisit that ancestor, we still cannot find them. Could it be because that transcription we did of the name all those years ago was correct? Sometimes it pays to go back and review the actual record that provided us with a name or place of birth. The transcription we did originally may be incorrect and could be the reason we cannot find the person.
Try a Genealogy Search on GenealogyBank.