This article from the Washington Post tells the stories of families who were separated at the U.S. border with Mexico due to the U.S. "zero tolerance policy," then reunited, and then separated again by Immigration and Customs Enforcement. "A federal court ordered the government to reunite the thousands of families separated under President Donald Trump’s zero-tolerance policy. But many of those parents were released from detention without any legal status in the United States. They were back with their children, but immediately subject to deportation — and re-separation," says the article.
