@anon27032421, I guess you will find your solution here: [RoonBridge on RPi strange audio setup behaviour - UUID?]
(RoonBridge on RPi strange audio setup behaviour - UUID? [SOLVED])
Quote from that thread:
RoonBridge generates and writes out a unique id into its data directory on first run and uses that to identify itself to RoonServer. Clear out /var/roon on the second device (or hunt down and delete the RAATServer/Settings/unique_id file) and it will generate itself a new one next time it starts up.