Unless ARC has lost authentication to Roon’s servers or the ROCK has gone offline, the “poor connection” message is accurate. Do you eventually see a green light in the Settings page next to RoonServer in ARC?
If you’re relying on UPnP autoconfiguration in Roon Settings → ARC, then the router might re-assign the port after a certain amount of time or a restart. A manual port forwarding rule will be more stable over long periods.
Please let us know if this message reaches you before you depart, as we’re available to assist with urgency. Thanks!