Those old TVs won’t connect to downgraded servers as well. This is due to the TV vendors not offering updated root certificates to verify encrypted connections. This is not so much Plex “abandoning” older smart TVs… though a 2013 model is pretty ancient to be fair.
If that’s the issue in your setup, you should be able to bypass this restriction by configuring your setup to only use unencrypted connections (set Settings > [Server Name] > Network > Secure Connections to Disabled; some clients have a similar setting in the app settings, I’m not 100% sure that’s the case with the SmartHub apps).
