Thanks for the update @kalich!
To confirm, you’ve also re-booted your router + Roon Server after attempting the above?
What are the current DNS settings on your Ubiquity router? Can you temporarily test out using Google or Cloudflare? That would be (8.8.8.8) or (1.1.1.1)
Here is some additional information from another thread you may find useful as well:
ROCK no longer connects after network change to Unifi/Ubiquiti UDM-Pro - #13 by Andrew_Stein.