Should be a fairly straightforward bit of airodump. Even if you don't capture the handshake, you can cross-reference the macs of stations associated with the AP of interest against the mac of your device. If the mac is randomized to a sufficient degree that you can't cross-reference it I guess you'd need to capture the association, but that shouldn't be a problem if you can turn the tv off/on and it does the thing consistently.

Even easier than that, set up an open WiFi network, see if the TV connects to it. Super easy for anyone that claims TVs are doing this to do.

Thank you kindly, that’s exactly the start I needed. Cheers