Should I daven Maariv with a Minyan that is Davening Mincha and Maariv within the time of Plag or should I Daven Beyechidus?

In such a case that both Mincha and Maariv take place after Plag and before Shekia, then it is better to Daven alone Beyechidus after nightfall. Davening Mincha & Maariv within Plag Hamincha Davening Maariv with a Minyan during Pelag Hamincha versus Davening in private after nightfall