'Caused' in the Bible

As a result, whenever the LORD raised up leaders for them, the LORD remained present with their leader, delivering Israel from the control of their enemies during the lifetime of that leader. The LORD was moved with compassion by their groaning that had been caused by those who were oppressing and persecuting them.

So the LORD caused those nations to remain and did not expel them quickly. He did not give them into Joshua's control.

Here's a list of nations that the LORD caused to remain in order to test Israel (that is, everyone who had not gained any battle experience in Canaan)