He @patterbt, had you been using the Tablo app on your smart TV before the firmware update as well, and it was better behaving? Or did this behaviour start when you got the TV and used the app on it?
Also to address your Netflix/Disney+ comparison, those apps just require an internet connection, by any means. Whereas an app being able to see a Tablo on your home network is not quite the same process. It involves looking at just your local network (LAN) to see if the device with the app is able to ‘discover’ other devices on your same home network, irrelevant to your actual internet access. Sometimes the Wi-Fi network frequency can affect what devices are seen. This is actually common with many smart home devices and systems.