To make it work, you need three devices; a Mac, a WiFi router, and a TV. If any of these three devices are not configured correctly, it might not work. I would suggest you turn off your VPN, firewall, or Antivirus app on your Mac and make sure that your TV is on the same WiFi network as your Mac. If you have a dual band router, use separate names for the 2.4GHz and 5GHz networks. Then make sure that both the Mac and the TV are on the same network. For example, if the Mac is on a 2.4GHz network, your TV should also be on that 2.4GHz network. If the Mac is on a 5GHz network, put your TV on the same 5GHz network. If you have a router with MAC address filtering, add the MAC address of your TV to the list of filtered devices. Rebooting your devices might also fix some issues. Give it a try!