Since you are using a Windows PC, I would verify that both Roon.exe and RAATServer.exe have been added as exceptions to your Windows firewall.
You can use these instructions to add the exceptions and the executables themselves would be located in your Database Location/Application folder path.
I would also add these exceptions to any Antivirus or other Firewall blocking applications you may have and ensure that you connected to your network via a Private network, not a Public one, see this guide for more information.
a. Realtek Drivers and are they up to date on the Win PC
b. Is there a Nehemic driver/service running. If so, try disabling it and re-try
c. Any other software that interfaces with the audio, studio programs, video capture, etc etc
Can you please try to temporarily host the Roon Core on the PC and see if you have the same issue?
Open Roon on the other PC you wish to try as the Core
Roon Settings -> General
Disconnect
On the “Choose your Core” screen, press “Use this PC”
If asked to Unauthorize, you can go ahead and do so. You are limited to one active Roon Core at a time but you are free to switch between them as often as you’d like.
Verify if the same behavior occurs on the different PC
If the PC as the Core works as expected, I suspect a firewall on the QNAP is causing this interaction.
Can you please try to reproduce the issue on System Output, note the exact local time + date + track it fails on and then manually send me a copy of your Roon logs by using these instructions?
I spoke to the team and they mentioned that one aspect we should also consider here is a firewall on the QNAP. To verify if the QNAP is playing a part in the issue, can I please ask that you temporarily switch Cores to the Windows PC?
Open Roon on the other PC you wish to try as the Core
Roon Settings -> General
Disconnect
On the “Choose your Core” screen, press “Use this PC”
If asked to Unauthorize, you can go ahead and do so. You are limited to one active Roon Core at a time but you are free to switch between them as often as you’d like.
Verify if the same behavior occurs on the different Core
Can I please ask that you reproduce this behavior with the Windows Core and send a new set of Roon logs? Once you switch the Core, the new logs should be written under %localappdata%/Roon on the Windows PC.