How is the Hebrew Bible different from the Greek Bible (Septuagint)?
Even in the earliest days, there were important differences between the Hebrew and Greek (Septuagint) Bible. The Septuagint increasing popularity meant many copies were in existence. They were written by hand and Scribes made mistakes which were multiplied. Notes and footnotes in the margin were added to the body of text.
Like all frequently copied manuscripts, the Septuagint went through a process of continual corruption. Therefore the Hebrew and Greek bibles diverged more widely.