The pop star and the former cast member of "The Hills," dated for nearly two years before splitting up last week, in part, because of their busy work schedules.
"Every time he wanted to come back and take meetings to get his career back in order, she would make him go to Asia and Europe," one insider told the celebrity news Web site.
"He hasn't worked and he wants to. They were both unhappy because he wants to have his career, she wants him to stay with her," the source said. "There is always a chance they will get back together. ... Brody is trying to set the ground rules and wants to be able to work. They have to find a balance."
Jenner is the son of Olympic decathlete Bruce Jenner and his former wife Linda Thompson.