Hi @Clark_Varnell,
So we can better assist you, please provide a brief description of your current setup using this link as a guide.
Make sure to describe your network configuration/topology, including any networking hardware currently in use, so we can have a clear understanding of how your devices are communicating.
If you control Roon from the Mac Pro instead of the iPad to the zones appear?
If you go to Settings > Audio on the iPad do you see all of the audio devices listed?