Thank you for listing those timestamps. I have taken a look at the received diagnostics package and as far as I can tell this is a networking issue somewhere along the line. I am seeing multiple issues here:
You are receiving “sleeping in read” messages in your diagnostics. This means that the streaming media is not reaching the endpoint in time
Your buffers from Qobuz are not being filled in time. This could indicate some network instability here. When this issue is occurring, are other devices on your network responding as expected? Are you able to successfully load web pages off of a PC connected to the same network?
Your Roon Remotes are spontaneously disconnecting and re-connecting to the Core. This also indicates that the connection to the Core is not stable.
Here are the possible areas to check on:
You mentioned that this issue occurs even when you have a second music server connected directly to the router with the switch out of the mix.
This leads me to believe that your router is either having hardware issues or your ISP is having issues upstream.
I would check to see if your entire network goes down when this issue occurs. You can do this by running a continuous ping test to google from a PC or from a mobile device. Instructions on how to run this from a PC can be locate here.
Similarly, you can use a ping test to ping your Core from another PC and see if it still responds as expected. You can use similar instructions to the article I linked, except for putting in Google’s IP address you’ll want to put in the IP address of the Core. The Core IP address can be found on one of your Roon Remotes in Roon Settings -> General. It should be listed as 192.168.X.XYZ or similar and you can run the ping test in command prompt using
ping -t 192.168.X.XYZ where X,Y,Z are the actual IP values.
Running these tests will give you some more information on where exactly the issue lies, since they will be happening outside of Roon. Once we can figure out if it’s the router going down or the network connection going down, then you can have some next steps here, e.g. replace the router or talk to the ISP to fix their connection. I do recall that you initially mentioned that HD video streaming works as expected but this does not give us enough evidence of stability since audio streaming requires better internet stability.
I look forward to hearing your thoughts on my above feedback.