Samsung S22 Ultra can't connect to Roon server despite network access (ref#77SCTU)

[Keith_Bergendorff]

Is Roon Server running?

· Yes, Roon Server is turned on and running.

What do you see on your screen?

· "Waiting for your Roon Server"

What happens if you press the "Select a different Roon Server" button?

· I don't see Roon Server.

Please try to restart your Roon Server by closing the Roon app in the taskbar or rebooting your Roon Server machine.

· No, the issue remains the same

Please try to restart your network setup by unplugging, waiting 30 seconds and then replugging in your networking gear.

· No, the issue remains the same

Please select how you've connected your Roon Server to the internet

· Roon Server is connected by *Ethernet*

Have you checked your firewall settings to ensure that Roon is allowed through?

· Roon still won't connect even after checking this aspect

Have you verified that Roon Server is on the same subnet as your Remotes?

· My Remotes and Server are on the same subnet and I still can't connect

Sometimes the issues can be resolved with a reinstall of your Roon Remote app. Let's try to perform a reinstall and see if it helps.

· I've reinstalled the Roon Remote but it did not help

What is the operating system of your Roon Server host machine?

· *Roon Optimized Core Kit* (ROCK)

Select any of the following components that are present in your local network setup

· *Mesh networks*

You mentioned a mesh network in your setup. Certain common mesh networks might require slight reconfiguration to support Roon.

· None of the above

Describe the issue

After a relatively trouble-free couple of months using my Samsung S22 Ultra phone as a controller, all of a sudden Roon on my phone can't make a connection to our Roon server, which is running ROCK 2.1 with tailscale on an i5 NUC hard-wired to our primary ASUS XT9 router. Strangely, I can enter the server's fixed IP address in Chrome on the phone and it brings up the server controls so the devices are in fact connected on the network, but for some reason the Roon app now reports that it can't find the server. Roon on my iPad still works fine but I need to use the phone as a controller. And yes I checked the firewall settings, turned off NordVPN on both ends, tried rebooting the server and the phone and the router, uninstalling and reinstalling the Roon app, switching to a different WiFi band on the phone, all to no avail. No physical or config changes to the network. I see that someone on the forum had a similar issue and it was never really resolved (ref# H6L31H). Any insights are welcome, thanks.

Describe your network setup

Intel NUC 5i5RWYH running ROCK 2.1 connected via Ethernet to primary ASUS XT9 router, which is connected to the ISP (Verizon 1Gb fiber). Secondary XT9 Router is connected to primary via Ethernet over Coax. There are two additional ASUS mesh routers (ASUS XT9 and RT66U) connected via WiFi to the primaries to extend coverage at front and back of the house. Firmware is up to date on all. Doesn't matter where in the house I'm located or which AP the phone is connected to, still won't connect.

[benjamin]

Hi @Keith_Bergendorff,

Thanks for writing in and for sharing all the details above!

@Keith_Bergendorff

Doesn’t matter where in the house I’m located or which AP the phone is connected to, still won’t connect.

What happens if you temporarily disable your mesh nodes, and only offer connection via your primary router? Do you run into the same issue?

I’d try to simplify your network setup as much as possible and see if you’re able to connect. In the meantime, we’ve activated diagnostics for your mobile device, if you could please open Roon (even if you can’t connect) it should allow us to review things further.

Thank you!

[Keith_Bergendorff]

Appreciate the quick response! Powered down the two extension routers and shut down and restarted Roon on the phone, but no change. This was actually the 2nd support request I started filling out, the first one at some point brought me to a page on the phone where I could specify the server’s IP to scan, and after entering it the Roon app connected and I thought I was cured, but next time I tried to use it it will no longer connect. Roon is open on the phone now but I’ll have to leave the house with the phone soon.

[Keith_Bergendorff]

Reconnected the two extension routers cuz there are other people living here that need the APs who could care less about Roon Nothing has changed, no troubles connecting with iOS but Roon on my phone can’t find the server. There was an Android update to V15 recently, I don’t know if that has something to do with it. Please lmk if there’s a specific time you can run diagnostics.

[Keith_Bergendorff]

FYI the Roon app on my HiBy R4 DAP which is running a customized version of Android V12 can still connect to the ROCK server with no problems, so I suspect this is an issue with V15. Unfortunately it can’t be rolled back without security risks.

[noris]

Hi @Keith_Bergendorff ,

Thanks for letting us know. I am looking over your account diagnostics and I see something strange here, it looks like the Roon app isn’t reporting an IPv4 address for your Android device. Are you using a duel IPv4/IPv6 network setup? Can you try to temporarily disable IPv6 to see if that helps?

[Keith_Bergendorff]

IPv6 is already (has always been) disabled on the network. Phone is currently at xxx.xxx.xx.30 assigned by DHCP.

[vadim]

Hello @Keith_Bergendorff,

Thank you for the update.

Samsung devices, especially high-end models like the S22 Ultra, come with several built-in services and settings that can interfere with apps trying to access LAN devices.

Issue: Knox or Secure Wi-Fi (a VPN-based privacy feature) can block or isolate traffic between apps and LAN devices.

• Go to Settings > Connections > More connection settings > Secure Wi-Fi, and make sure it’s disabled.
• If you’re using Knox Manage (for enterprise), ensure Roon is not being sandboxed or restricted in LAN access.

Issue: Roon might lack permission to access the local network after a system update.

• Go to Settings > Apps > Roon > Permissions, and check:
  • Nearby Devices — should be allowed.
  • Local network access if shown (some Android versions don’t show this explicitly).
  • Also ensure Battery optimization is set to “Unrestricted” (not “Optimized”).

Issue: Samsung phones with Private DNS enabled may fail to resolve local .local hostnames or LAN IPs reliably.

• Go to Settings > Connections > More connection settings > Private DNS, and set to Off temporarily.

[Keith_Bergendorff]

Wish I could say I investigated the situation scientifically by varying each combination of potential factors to pinpoint what the connection problem was, but “Ain’t nobody got time for that!” As of now Roon appears to be working just fine on my phone and I can access all our endpoints throughout the house. I reinstalled the OS (V2.1 build 271) and restarted the server (ROCK 2.51 build 1534) so that might have had an effect. FTR there are no options for Secure WiFi or LAN Access on my phone. I enabled all permissions for the app. Private DNS is set to Automatic, Nearby Device Scanning and Unrestricted Battery were already enabled. For the moment Roon ARC is also merrily streaming in my car again, don’t know if the connection issues were related. I see other users are having some issues getting Roon to work properly with Android’s latest OneUI 7 interface on newer Samsung phones (I’ll be trading up next month), we’ll see how it goes from here.

Appreciate all the prompt assistance from the Roon team!

[vadim]

Hello @Keith_Bergendorff,

Thank you for the update! We’re glad to hear that everything is running as expected.

The issues related to OneUI 7 are currently being actively investigated by our R&D team and will be addressed in future releases. However, at this time, we don’t have an exact timeframe for the fix.

Enjoy your music!