Unable to join Apple music subscription even if they are part of Family plan

I recently changed my Apple music subscription through Verizon to a family plan. My wife and son are already listed as members of my family. When i look on their phones it shows that I am sharing the subscription with them, but when we try to go to Apple music it keeps telling us that they need to subscribe. How do I get them to be able to use our shared subscription?

[Re-Titled by Moderator]