To enjoy the latest features available on Chromecast or Google TV Streamer, your device might need to update to the most recent software version. The update is done automatically as part of the setup, so you don't need to do anything.
If you have a Chromecast with Google TV or Google TV Streamer, the update doesn't appear in the Google Home app. You need to access your Chromecast updates from your TV. To do this on your Google TV home screen, choose All Settings 
Note: During the update, the Google streaming device isn't available to cast. Wait until the update is complete to try to cast.
Here's an overview of what you should expect during the update:
- Your Google Home app provides indication of the setup progress.
- You can check the status of your update on the Google TV home screen.
- You can use the LED on the streaming device to verify that it's updating.
- The update typically takes 10-12 minutes. The streaming device LED light pulses while it receives the update. Refer to Chromecast and Google TV Streamer LED light for details on what the LED light patterns mean. You may also want to check on connectivity and power availability if the update takes much longer than expected.
- If needed, you can reboot the streaming device to automatically restart the update. Unplug your device from the power source and then wait for one minute before you plug it back in.
If the issue persists, factory reset the device and try to set it up again, preferably on a 2.4 GHz network, if available.