If your son doesn't know, download NMAP and run a scan from your PC to your TV client IP on same subnet. It should produce what ports are open. Depending on what firewall you have you can block those ports that are open and unneeded. Tvs are always broadcasting over ports outside of 443, 53, and 80. Most of which are telemetry and other BS that collects info on you. Another great way to stop some of this is installing a Raspberry Pi and installing PiHole, a DNS sink hole, that blocks a lot of these unwanted and needed services that will also speed up your internet because your not eating up your bandwidth with these unneeded programs. I'm sure you son blacklisted the mirror casted mac address device. There is that option as well. You can also change your dns provider in your router to cloudflares family and malware servers where it blocks porn and malware and has a list of hijacked dns servers that they will block you accessing.
