Communication is a key aspect of both managing a team and operating as a member of a team. As the PM, having a member who is unresponsive and lacks either communication skills or the desire to make an effort to communicate can be detrimental to the progress made on the project. Ideally, everyone on the team has a specified set of roles and responsibilities. Someone who doesn’t know what their responsibilities are, or who doesn’t inform other people who are relying on them of their progress hurts everyone around them by not communicating. To answer your question of how it can be handled. To be honest, I don’t think anyone who lacks rudimentary and essential communication skills should be an essential member of any product development team due to the negative effect it can have on others and overall progress. So, talking to said person one on one about what they need to improve in regards to their communication skills could remedy the issue, and if not it could be necessary to find a replacement.