Hey @Andrew_Bovingdon — Thanks for reaching out, and apologies for the difficulties here!
Can you confirm the firmware version of these devices? Apple recently removed Airplay 1 support from the Airport Express devices, so devices on the latest firmware are not compatible with Roon.
This thread includes information on rolling back the firmware on yout Airport Express devices:
Check out our documentation on using Squeezebox devices with Roon. If everything appears to be setup correctly then there may be some networking difficulties at play here that we will need to look into.
Can you describe your networking setup, including all networking hardware in use and how your devices are connected?
Thanks!