Screen mirroring between your Mac and your Smart TV relies on your local network. Both devices need to be connected to the same local network. When you are using different subnets or a guest network in your house or office, please make sure that both the TV and the Mac are directly on the main network that is created by your router.
This is what you should look for on your Mac and on your TV:
Your Mac has an IP address. This is the address that it gets from your router. Note that the first three sets of digits are 192.168.10.
Your TV has an IP address as well. When the first three sets of digits are the same as on your Mac (screenshot 192.168.10), this means that the TV is on the same network and the same subnet as your Mac.
For Screen Mirroring to work correctly, it is important that your TV can reach your Mac to get the mirroring video stream. The easiest solution is to disable the Firewall on your Mac . If you do want to have the firewall enabled on your Mac, please make sure that you allow incoming connections to the Mirror for Smart TV app.
III. Don’t put your TV in Screen Mirroring mode.
The “Screen Mirroring” (as a source on TV), interferes with our app. Please leave the TV in “TV Watching” mode (as the selected source) or any HDMI IN as a source