Can you try using your smartphone and accessing xbvr through its web browser? That should let you know if there's some network issue, and not just HereSphere.
Viewing post in My Heresphere can’t connect to Quest 3—via SMB or XBVR.
If you can't load it in your phone's web browser, then the issue stems from your Mac/router/xbvr. You can try asking for help on the xbvr discord: https://discord.gg/wdCHXAG. Maybe some recent MacOS updates are preventing xbvr from communicating properly over your network.