"Patrick has been trying to reach Miley since he's been back, calling her over and over and she hasn't been answering his calls," eonline.com quoted a source as saying.
"He's very upset and is doing everything he can to try resolve things. Patrick is extremely frustrated because he's been actively trying to be very good and to make this relationship work," the source added.
Patrick was photographed getting cozy with a bikini girl during his vacation. He denied rumours that he cheated on Cyrus.
"Omg. It's one of my best friends girlfriend... Would NEVER do anything against my GF... Girls have guy friends and guys have friends that are girls," he said.
However, new rumours have spread that Patrick was with his ex girlfriend in Cabo. Meanwhile, Miley is partying alone and not even commenting on the clarification that her boyfriend gave after his cosy pics went viral.