I can no longer see when a participant joins a meeting

As of last week I can no longer see when participants have joined my meeting. They are still receiving the message to wait until the host let's you in but I can't see they are waiting to let them in. Once I realised that it was continually happening I suggested they leave the session and rejoin and they all got in no problem and I received the message they were waiting?

Any thoughts why and how I might remedy? 

Also when I am waiting for them to join even though they have said they are waiting it is only displaying as one participant in the meeting?