A source tells PEOPLE Madonna flew to London to take care of son Rocco after ex Guy Ritchie left him "alone" upon settling their custody dispute

By Jeff Nelson
September 15, 2016 01:45 PM

Madonna and Guy Ritchie‘s custody battle may have come to an end, but the exes’ relationship rearing their son seems as contentious as ever.

The pop icon flew to London because she was “concerned” about Rocco, 16, when his father and stepmother, Jacqui Ainsley, allegedly “left him alone” to take a trip to L.A. just days after news of their resolved custody battle, a source tells PEOPLE exclusively.

The source adds the Ritchies’ trip overlapped with Rocco’s first day of a new term at school.

“Her kids’ education is the most important thing to Madonna,” says the source. “She takes their schooling very seriously.”

Ritchie’s rep is not commenting.

Rocco and Madonna
Madonna/Instagram

Ritchie sources told PEOPLE back in January the British filmmaker prefers to employ a more laid-back parenting approach.

“He wants Rocco to have the confidence he lacked growing up and thinks Madonna’s stern parental style is counterproductive,” a Ritchie source previously said. “The welfare of Rocco is Guy’s priority.”

Madonna was photographed arriving at London’s Heathrow Airport on Monday, and she’s been spotted out and about the U.K. capital throughout the week.

On Tuesday, she stopped by Rocco’s new school for about an hour and “was very friendly with the teachers and was very relaxed,” a source told PEOPLE of the visit.

Later that night, the mother-son duo enjoyed a quiet dinner at nearby Notting Hill hotspot Farmacy with family friend Benjamin Khalili, a museum curator.

RELATED VIDEO: Madonna and Guy Ritchie’s Custody Battle over Son Rocco

“There was just a really good vibe. Everyone was smiling and laughing the whole evening. It was a very nice evening for them all,” an onlooker told PEOPLE at the time, adding Rocco “was just loving life and spending quality time with his mum.”

Madonna
Mike Marsland/WireImage

On Thursday, Madonna got back to work, making an appearance at the star-studded premiere of the Ron Howard-directed Beatles tour documentary Eight Days a Week while she was in town.

Madonna and Rocco’s reunion came less than a week after the pop star’s custody dispute with Ritchie ended; last week, Ritchie’s lawyer told the Associated Press Rocco will remain predominantly in his father’s care in London.

The bitter eight-month-long battle over Rocco began in December when Ritchie, 47, refused to return Rocco to his mother for the holidays, despite an order from a New York Supreme Court order to do so.

The exes’ lawyers hashed it out at a court hearing in March, and the pair appeared to come to a détente in early June, when all parties forwent a scheduled court appearance and court documents showed a motion pending on the case.