The Wanted singer is said to have broken up with his girlfriend after he and the model started to want "different things out of the relationship".
Speaking to The Sun on Sunday newspaper, a source revealed: "It was hard for Max to dump Nina so soon after news broke that The Wanted are breaking up.
"But they just wanted different things out of the relationship and had grown slightly apart."
However, despite the breakdown of his relationship and the 'All Time Low' boy band, Max is said to be staying "optimistic" during such a "challenging time".
The insider added: "It's a challenging time for Max as he's going through big changes in his personal and private life.
"But he is being optimistic. He is looking at it all as an opportunity for a fresh start. He's not one to get down in the dumps about things."
Even with Max trying to be upbeat, he spoke last year about how happy he was being in a relationship with someone he considered his "best friend".
He previously said: "I'm very happy now. For the first time I am with a girl who is my best friend.
"She's funny, calm and nice with everyone - the boys, my family. I feel settled."