Why can I broadcast on my neighbor's TV on my wifi

I've recently noticed that a new device appears as available for streaming from my Android phone when I'm connected to our home Wifi network. It's a LG Sk8100 television, but since we do not own it, I guess it's the neighbor's.

Since our Wi-Fi network is protected by APS WPA2-PSK and I did not share the key with the neighbor, I'm afraid our network will be compromised.

Curiously, when checking the list of devices in the router, no TV appears in the DHCP client list or wireless connections for 5 GHz or 2.4 GHz networks. The only devices connected are my desktop and my Android phone.

So, why can I stream this LG Mystery TV when I connect to our Wi-Fi network, while this type of TV does not seem to exist in the list of devices attached to the router?

The TV does not show if I disconnect the wifi or if I leave our apartment. It only appears when it is connected to our Wifi network. If I try to make a call there, the connection times out and fails. I speculated that something Google was related to the location, but it still exists with the location on the phone.

[edit] It also seems that the only application that can "see" ghost TV is YouTube for some reason. I think it will be a whim of Google software rather than an attack, but maybe someone here recognizes the problem and has a say.