Prior to the big trade between the Brooklyn Nets and Philadelphia 76ers, James Harden had begun disconnecting from his Nets teammates. Prior to Kevin Durant's injury, he and Harden were barely communicating.
Durant was injured in mid-January. That means there was likely over a month that the two stars weren't really speaking.
In recent weeks, Harden began cutting off communications with all of his Nets teammates. It was Harden's way of sending a message that he no longer wanted to be in Brooklyn.