The sources maintain that busy work schedules proved to be a great challenge for them both, although they are still in regular contact and remain friends.
Reps for Hough and Seacrest declined to comment.
The American Idol host and media mogul, 38, and former Dancing with the Stars pro and actress, 24, have spoken candidly in the past about juggling career and a relationship.
"It's a hard thing to do, especially when you're so caught up in your work and bettering yourself," Hough recently told PARADE. "I think at the end of the day you have to find a balance with what's really important."
After ringing in the new year, the duo enjoyed a romantic getaway in St. Bart's days later.