Katie, 40, and Jamie, 51, walked their first red carpet together as a couple at the Met Gala on May 6.
They were photographed together for the last time less than two weeks later on May 14.
"They are so great and Katie is always so chic. They were wonderful. They're really good, really great," Corinne told People at the time.
It appears Katie and Jamie split sometime during the third weekend in May. Katie took her mother Kathleen as her date to the American Ballet Theatre 2019 Spring Gala on May 20. Meanwhile, Jamie attended F. Gary Gray's Hollywood Walk of Fame star ceremony solo on May 28.
Instead of spending July 4 with his longtime love, Jamie was photographed playing volleyball at Leonardo DiCaprio's house in Malibu. He brought his rumored new girlfriend Sela Vave to the party, according to RadarOnline.com.
Sela also accompanied Jamie to the Apollo in the Hamptons event on Saturday, August 3.