Roon Core Machine
Macbook Pro, Early 2015 (8GB RAM, core i5, macOS Monterey)
Networking Gear & Setup Details
Telia wifi router, 2.4GHz, no VPN
Connected Audio Devices
Apple TV, Macbook Pro, iPhone SE
Number of Tracks in Library
about 5000 tracks, mostly FLAC, total size about 100GB
Description of Issue
I upgraded Roon Core to 2.0 on macOS and installed ARC on iOS (iPhone SE, 2nd gen, 256GB). Configured port forwarding for network access and verified downloading tracks via wifi and streaming via wifi and 4G was working with a few tracks.
After that I started adding local albums to download queue in Roon ARC iOS to make them available offline. After adding about 1500 tracks (and successfully downloading a few tracks), ARC app started showing Core unreachable message. When I restart the app, it shows black screen about 3-4 minutes and after the ui loads, there is Core unreachable message below the screen. Download queue is stuck at 7/1499. Downloaded items are playable in the app, other tracks in the Roon library are visible but not playable in ARC (as expected). I verified wifi connection is ok on MBP and iPhone (fast.com shows 60-70Mbps on 100Mbps connection). I also checked that Roon remote app running on iPhone can see and control Roon Core on MBP.
Please advise how to make ARC app usable in online mode and start downloading the queue again