I renewed the maintenance on my DRS but am still getting the "Maintenance expires in XX days" message at the topt when I open DRS. What mechanism after renewal prevents the message from appearing?
Clicking the I already paid button takes me to my customer portal but I'm not sure what to do there.
Sounds like you need to apply the new license key, you should find this by logging into the customer portal and going to the licensing page.
If the license doesn't fix the message issue, contact support.