But that’s just not true?
Anyone who spends time reading primary sources will know that there was no standardised spelling in Tudor times. I’ve even come across “king” written in different ways in the same paragraph: “king”, kinge”, “kyng” etc. It’s quite funny at times.
And the Boleyn family’s surname is no different. There are so very many variations of it in 16th century sources, but “Boleyn” does seem to be the most common.
Read more in my article “Boleyn or Bullen – The Spelling of Boleyn and the Myth that Anne Boleyn Changed It”.