I did some experimentation just now.
I have Roon ARC on two devices:
- iPad Air on Wi-Fi.
- Google Pixel 6 Pro on mobile (Wi-Fi turned off for this experiment).
On both devices, Roon ARC works fine. When I open Roon ARC, it updates after about 4 seconds to show the recent albums I was playing last night, so that’s good.
Then, using the Roon app on my laptop, I restored the latest backup made in the early hours of this morning. My laptop uses Pop!_OS (Linux), so I run Roon in Bottles (alternative to Wine), but I don’t think this is relevant.
At the end of the Restore process, I see this:
The IP address is correct, so I don’t know why it says Connection failed.
So I closed the Roon app and then opened it again. Now it said this:
Sorry about the tooltip in the screen capture, but you can see it no longer says Connection failed and now says Ready. So I pressed the Connect button to proceed. Now Roon is running again after the restore.
Looking at Settings / Roon ARC, everything is well:
And according to my router, everything is well there too:
But starting Roon ARC up again on my two devices, both of them initially say, Poor connection, shortly followed by, Can’t connect to your Roon Core. There is a message at the bottom of each device saying, Core last seen x days ago (9 days in the case of my iPad, and 4 days in the case of my phone).
So the problem is reproducible.
As I mentioned before, my approach to fix it is to use the Reset Roon ARC command at the bottom of the Roon ARC options. But then Roon ARC shows two possible Cores:
If I catch it while it says Online and ready, I can connect and then all is well, but it seems to struggle to get to this state and most of the time, looks like this:
I hope this information helps.
P.S. Looking at the Pi-hole Query Log with a search for “roon”, there does not seem to be any domains being blocked.