Explanation
The project manager should handle this situation by using conflict resolution techniques to facilitate a constructive dialogue among the team members and reach a consensus on the new feature. According to the PMBOK Guide, conflict resolution techniques include problem-solving, compromising, smoothing, forcing, and withdrawing1. In this case, problem-solving is the most appropriate technique, as it involves analyzing the root cause of the conflict and finding a mutually beneficial solution1. Bringing the team members to the meeting room is an example of problem-solving, as it allows the project manager to address the issue in a private and respectful manner, and to clarify the expectations and requirements of the new feature. This way, the project manager can resolve the conflict and get the team to complete the task.
References: 1: PMBOK Guide, 7th edition, page 95.