Hello @peter_derousse,
Are you by any chance making use of multiple VLANs or AP Isolation turned on for your setup here? Roon requires all your devices to be on the same VLAN as to properly route multicast traffic and for our device discovery protocols. I would also make sure that all your devices are on the same subnet range and if you have the option for “flow control” on your Unifi devices, sometimes turning this option on has resolved issues (Loss of the remote connection to the Roon server). Please let me know if this helps.
Thanks,
Noris