Read it in a book called ‘Armaghan e Ajam’ (discussing the concepts and stories that were adapted by Muslims from their previous faiths) written by Uzair Ahmed (pages 110-114 of the book) that this a fictional character.
I also find some blogs / articles discussing the same issue. What is your view on this. Whether Hazrat Owais Qarni’s (RA) biography is mentioned in any of the authentic Sunni / Shia books?