My Sony Google tv will no longer turn off using google assistant on my google hub

[BenClf]

1. Having had Google Assistant turn my Sony TV on and off for many years it now no longer works. I have tried resetting the TV to its original settings and registering it all again. I have also Removed the device from the Google home app and when I have re-added it, it has appeared as a local device which I can now no longer delete. This is so frustrating because it used to work absolutely brilliantly for years. But now I can no longer say okay Google turn off the kitchen TV. When I do it just says sorry that device has not been set up yet. When I set it up and say okay, Google turn the kitchen TV on it says okay turning kitchen TV on, but the TV doesn’t come on. Any help from anybody with regards to this issue would be much appreciated.

[GeremiG]

Hi @BenClf!

Thank you for posting in the community. I'm sorry to hear that your Sony TV is not turning on or off when you use a voice command through your Nest Hub. I appreciate your efforts in taking those steps before. I'm happy to help you! 
To help me find the best solution, I'll need to ask you a few questions:

• What model is your Sony TV?
• Does your TV have Google TV or Chromecast built in?
• Is HDMI-CEC (also known as BRAVIA Link or BRAVIA Sync on Sony devices) enabled on your TV?
• Is your TV and Nest Hub up to date?

If your TV is listed under ‘Local Devices,’ this means your TV is connected to the same WiFi network your phone is connected to; however, the TV is not added to the Google Home app. 
Here is an article that might be useful for you to add your Sony TV to the Google Home app: Link your TV to your Google Nest or Home speaker or display.

Please keep me posted. I'll be waiting for your response.

Best regards,
Geremi