Hi @lyroon,
That error looks like you’re trying to start Roon Radio and it fails to communicate with our servers to start properly. If you reboot the Core is the issue the same? Does the issue only occur on Roon Radio? If you try to queue up a playlist of tracks, do they all play properly?
I would check the DNS setup you have, we have seen users have a better experience if they change the DNS to Cloudflare DNS, Quad9 or Google DNS. It seems like Freebox has all of their documentation in French, so this is what I could find: