Initially expected in the U.S. for a hearing Wednesday, the singer and her British director ex are now due in New York Supreme Court March 2 to sort out Rocco's custody.
While he spent a couple months on the road with his mom during her Rebel Heart tour in the fall, the teen left to live with his dad in the beginning of December. And when he refused to return to Madonna's custody for the holidays, a judge reportedly ordered he return to the U.S. to sort out his living situation.
Despite the judge's order, Ritchie has yet to return Rocco to his mother after two months.
In between tour legs, Madonna, 57, flew to the U.K. for the weekend to make a plea for her son to return home – but it was no "Holiday."
"She was hoping to persuade Rocco to come back to New York . . . but Rocco reiterated his determination to stay in London," the Ritchie source says. "It was a series of short, difficult conversations between Madonna and Rocco." (The source adds Madonna and 47-year-old Ritchie – who finalized their divorced in 2008 – only communicate through their attorneys.)
As a source previously told PEOPLE, Rocco wants to remain with his father because he misses his friends in England and prefers his dad's more laid-back parenting style.
Madonna / Instagram
For Ritchie's part, "It's about a fundamental difference in parental philosophies," the Ritchie source adds, adding the filmmaker views his ex's "old-school" approach as "counter-productive" and "harming his self-esteem and confidence at such a crucial part of his life."
Meanwhile, Madonna – now in Taiwan for the Asian leg of her tour – worries about her oldest son's scholastic pursuits, as an insider close to the singer alleges he has missed some school since leaving her tour.
"He should have been home already," the insider told PEOPLE in January. "Madonna is a devoted mother, and a big priority is her children's education."
Another source – a friend of the former couple – recently told PEOPLE Madonna is upset by the custody dispute but that she is ready to fight for her son.
"She is not happy. She is an excellent mother, and people can say whatever they want – but her children mean the world to her," the friend said. "She is going to fight, fight, fight, and she is going to fight to the end."
Reps for Madonna and Ritchie did not respond to PEOPLE's request for comment.
Reporting by SARA NATHAN