@Ganesh_Gunaratnam, are you seeing an error message under Settings → Roon ARC? If so, can you post it here? Also, was ARC working previously on your mobile network and it does not work now, or was it never working for you?
Please see @Suedkiez’s comment above, as a mobile connection to ARC will require either UPnP or a port forwarding rule in your router’s web GUI pointing to the IP and listening port from your screenshot.
Is your Core hardwired to the UDM, to a switch, or to an access point? It also appears you’re using a managed switch, so please also verify that your Core is not on a separate subnet from the main router.
We’ll keep an eye out for your response and go from there.
Hi after seeing the error I created a rule to do the port forwarding and tested it on the phone by turning off WiFi and it seems to work.
As for your other questions, yes the NAS is Hardwired to switch.
Thanks @connor and @Suedkiez for the Prompt replies