Contradiction with Numbers 34:2-12
Joshua 23:4 states that God has allotted lands to the Israelites, but Numbers 34:2-12 provides a different description of the boundaries of the lands inherited by the Israelites.
Numbers 34:2-12: Command the children of Israel, and say unto them, When ye come into the land of Canaan; (this [is] the land that shall fall unto you for an inheritance, [even] the land of Canaan with the coasts thereof:)
Contradiction with Judges 2:21-23
Joshua 23:4 suggests that the land was given to Israel, yet Judges 2:21-23 explains that God left some nations to test Israel, implying not all land was fully given.
Judges 2:21-23: I also will not henceforth drive out any from before them of the nations which Joshua left when he died:
Contradiction with Judges 3:1-6
Joshua 23:4 mentions the distribution of the land, but Judges 3:1-6 indicates that certain nations were left to prove Israel, suggesting the land was not fully conquered.
Judges 3:1-6: Now these [are] the nations which the LORD left, to prove Israel by them, [even] as many [of Israel] as had not known all the wars of Canaan;
Contradiction with Joshua 13:1-7
Joshua 23:4 talks about the division of the land, yet Joshua 13:1-7 mentions that much of the land still remains to be possessed, indicating an incomplete distribution.
Joshua 13:1-7: Now Joshua was old [and] stricken in years; and the LORD said unto him, Thou art old [and] stricken in years, and there remaineth yet very much land to be possessed. [to...: Heb. to possess it]