Thank you for reporting your issue and for your patience in awaiting a response.
I tried to get diagnostics info from your setup and haven’t received a response yet. Perhaps this might help though. I use Kaspersky on all of my PCs and when I updated I was dropping connections left and right. This wasn’t just Roon either so perhaps my first sentence is relevant. Can you check your system preferences under network and see if there are any filters being used? Also, see if the firewall is enabled and try disabling it just for a test.
I typed this and checked again. There’s been no response from your core since my diagnostics inquiry so we might be onto something here.