The Google Home app loses connection to smart devices more often than you'd expect. First, make sure your phone and the devices are on the same Wi-Fi network — the app doesn't work across different networks or when your phone is on mobile data. Restart the app, then power-cycle the device by unplugging it for 10 seconds. If that doesn't help, go to Settings → Wi-Fi and forget the network, then reconnect.
If your Nest or Home speaker stops reacting to 'Hey Google', check the microphone mute button on the device — it's easy to hit by accident. Also open the app and verify the device is still linked to your account under Devices. Sometimes a simple factory reset followed by re-setup in the app fixes persistent unresponsiveness.
Automations that used to work just stop firing. Common reasons:
The app hangs on the home screen or takes 20+ seconds to load devices. Clear the app cache on Android via Settings → Apps → Google Home → Storage → Clear Cache. On iOS, delete and reinstall the app. Also check that the app is updated — older versions have known rendering bugs on newer OS versions.
Nest camera streams show a black screen or infinite spinner. This almost always comes down to bandwidth — live video needs at least 2 Mbps upload on the camera side and 2 Mbps download on your viewing device. Check your router's upload speed and move the camera closer to the access point if signal is weak. If the stream loads in the app but not on a Nest Hub display, restart the display from the app.
A device vanishes from the interface after a network change or app update. Open the app, tap Add → Set up device → Works with Google and check if the device reappears as unassigned. If not, remove it from your account completely and go through the full setup again.