Unable to downgrade Apple Music from Family to Individual Plan

Hello NJAnalyst,

Thanks for posting in Apple Support Communities. It looks like you are on Mac so try the following from How to switch to a different subscription plan - Apple Support which should allow you to switch to an individual Apple Music subscription.

"Switch your subscription plan on your Mac

1. Open the App Store app.
2. Click the sign-in button  or your name at the bottom of the sidebar.
3. Click Account Settings at the top of the window. You might be asked to sign in.
4. On the page that appears, scroll to Subscriptions, then click Manage.
5. Click Edit next to the subscription that you want to change.
6. Choose a different subscription option. 
7. If you chose a subscription that you can share with family, select Share New Subscriptions. (Don't see Share New Subscriptions? Set up Family Sharing or join a family, then return to this page and turn on Share New Subscriptions.) If you don't want to share the subscription with your family, turn off Share New Subscriptions."

All the best.