Contradiction with Genesis 11:2
Genesis 11:2 mentions that people moved from the east, while Genesis 10:30 describes the descendants of Joktan spreading to the east.
Genesis 11:2: And it came to pass, as they journeyed from the east, that they found a plain in the land of Shinar; and they dwelt there. [from...: or, eastward]
Contradiction with Genesis 11:9
Babylon is described as the origin of languages dispersing, contrasting with Genesis 10:30, which establishes settlements in regions rather than dispersions from Babylon.
Genesis 11:9: Therefore is the name of it called Babel; because the LORD did there confound the language of all the earth: and from thence did the LORD scatter them abroad upon the face of all the earth. [Babel: that is, Confusion]
Contradiction with Numbers 34:3-12
Defines territorial boundaries for Israel that differ from the locations mentioned for Shem's descendants in Genesis 10:30.
Numbers 34:3-12: Then your south quarter shall be from the wilderness of Zin along by the coast of Edom, and your south border shall be the outmost coast of the salt sea eastward: