Hi @Roderick_Laird,
Thank you for the report. Based on your description, you’ve exhausted most of the external variables that might have changed here.
You reported this issue not long after we launched ARC in 2022 - did you resolve it initially by creating the aforementioned port forwarding rules?
The port test pings an upstream server and listens for a response on the assigned port; it does not test the downstream connection to the phone, and it will retain a “Ready” status until the same port test fails, regardless of whether ARC is actively capable of connecting or not. So, a failing cellular connection to ARC with a positive port test indicates that either:
a) the downstream connection, another app or the phone OS, or ARC itself is the blockage
or, in rare cases:
b) RoonServer’s upstream connection can send a ping, but it’s is being filtered sufficiently that ARC can’t sync
Just in case, what happens if you augment the port assignment you’ve hardcoded in the port forwarded rules by a few hundred? It’s unlikely the port test would miss a port mapping conflict, but this is worth a try.
Do you have any QoS rules in your Ubiquiti router that might be throttling RoonServer’s upstream connection at times?
Are you encountering any popup errors or banners? Please share a screenshot of the screen when you lose connection after switching to cellular.
We’ll escalate from there. Thank you!