The Direct Messages screen has two different tabs: Primary and Requests. The Primary tab displays both unread and old conversations with people you are “connected” to. Click on a conversation to view the message and send a reply.
People you are "Connected" to:
- someone you follow
- someone who follows you
- someone in your gym
- someone in the same coaching program
The Requests tab shows you messages from people you aren’t connected to you. Keep those conversations in your Requests tab or move the conversation over to the Primary tab by connecting with that user via one of the connection options above.