"It was a heavy breakup for both of them because they were so excited about their future together," the insider added. "The full-time transition to Nashville [for Holly] was their biggest hurdle and it just didn't work out in the end."

Meanwhile, a second source shared, "Holly knows this is the best for her. She realized he wasn't the person that she thought he was and that the person who he portrays on TV is not his authentic self. At some points he was good but Holly held onto the fact that he is a good guy because they come from similar backgrounds. At the end of the day the fame changed him."

Their second split comes four months since Pell's appearance on The Bachelor Winter Games. After the show aired in February, he revealed that he had ended his brief fling with fellow contestant Stassi Yaramchuk after the show because he still had feelings for Allen.

"During that time, I really started reflecting on where my heart was at and I started thinking a lot about my ex, honestly," he told People in February. "I went on the show to find love, and I did find love...It made me realize where my heart was, and that was to reconcile with my ex."