Contradiction with Joshua 15:7
This verse describes the boundary from Debir northward to the valley of Achor, which contrasts with the direction and location described in Joshua 18:13.
Joshua 15:7: And the border went up toward Debir from the valley of Achor, and so northward, looking toward Gilgal, that [is] before the going up to Adummim, which [is] on the south side of the river: and the border passed toward the waters of Enshemesh, and the goings out thereof were at Enrogel: