Contradiction with Genesis 46:10
Numbers 26:39 mentions a descendant of Benjamin, whereas Genesis 46:10 discusses the descendants of Simeon.
Genesis 46:10: And the sons of Simeon; Jemuel, and Jamin, and Ohad, and Jachin, and Zohar, and Shaul the son of a Canaanitish woman. [Jemuel: or, Nemuel] [Jachin: or, Jarib] [Zohar: or, Zerah]
Contradiction with Numbers 1:22
Numbers 26:39 lists the descendants of Benjamin, but Numbers 1:22 enumerates the descendants of Simeon.
Numbers 1:22: Of the children of Simeon, by their generations, after their families, by the house of their fathers, those that were numbered of them, according to the number of the names, by their polls, every male from twenty years old and upward, all that were able to go forth to war;
Contradiction with 1 Chronicles 7:14
Numbers 26:39 refers to the descendants of Benjamin, whereas 1 Chronicles 7:14 talks about the sons of Manasseh.
1 Chronicles 7:14: The sons of Manasseh; Ashriel, whom she bare: ([but] his concubine the Aramitess bare Machir the father of Gilead:
Contradiction with Judges 20:44
Numbers 26:39 records census data of the tribe, while Judges 20:44 discusses a battle outcome.
Judges 20:44: And there fell of Benjamin eighteen thousand men; all these [were] men of valour.