A source close to the show tells ET that the reality star was actually fired from the popular Bravo series. DailyMail was first to break the news on Tuesday.
"The reunion was the final straw," the source says. "Dorinda was very aggravated all season long and it was too difficult to work with her."
"It's obvious she needs to work on herself," the source adds. "The reunion was rough and she wouldn't acknowledge her bad behavior."
A second source tells ET that Medley's exit from RHONY was more of a mutual decision.
Medley, who has been with RHONY since the show's seventh season, announced her exit via Instagram on Tuesday.
"What a journey this has been. I have laughed and cried and tried to Make it Nice... but all things must come to an end," she shared. "This was a great outlet for me to heal when my late husband Richard passed away."
"I have met so many interesting people and learned so much about myself, about life and about women along the way," she continued. "Thank you to Bravo and NBC for the incredible ride and to my cast mates for constant stimulation and entertainment. I wish you all health, happiness and success. Clip! Dorinda."
A source close to the cast told ET earlier on Tuesday that the other women on the show found out about Medley’s exit shortly before she posted the announcement online. They're all surprised and going to miss her, the source added.