Contradiction with Genesis 42:6
Joseph is not recognized by his brothers, contradicting their mission of buying specifically from him.
Genesis 42:6: And Joseph [was] the governor over the land, [and] he [it was] that sold to all the people of the land: and Joseph's brethren came, and bowed down themselves before him [with] their faces to the earth.
Contradiction with Genesis 37:28
Joseph is sold into Egypt, which contrasts them going to Egypt, now dependent on the very land they sent him to.
Genesis 37:28: Then there passed by Midianites merchantmen; and they drew and lifted up Joseph out of the pit, and sold Joseph to the Ishmeelites for twenty [pieces] of silver: and they brought Joseph into Egypt.
Contradiction with Genesis 37:10
In Jacob's earlier vision interpretation, the brothers bowing down was questioned, contrasting their later trip to Egypt.
Genesis 37:10: And he told [it] to his father, and to his brethren: and his father rebuked him, and said unto him, What [is] this dream that thou hast dreamed? Shall I and thy mother and thy brethren indeed come to bow down ourselves to thee to the earth?
Contradiction with Genesis 37:8
Brothers' resentment contradicts their later act, as they previously refused to accept his potential leadership.
Genesis 37:8: And his brethren said to him, Shalt thou indeed reign over us? or shalt thou indeed have dominion over us? And they hated him yet the more for his dreams, and for his words.