Hey there Jeevan,
Sorry to hear about the issues you're having with your Chromecast while using a 3rd party app, I'm sure it's frustrating, but I'm happy to look into this for you.
First off, would you mind trying each of the following before moving on to the next:
- Turn your iOS device OFF and back ON
- Are you using the Google Home app
that replaced the Chromecast app?
- Are your Apple devices on current Minimum system requirement?
- Turn on Bluetooth:
- On the home screen, tap Settings > Bluetooth.
- Make sure the slider is On (toggled to the right and green).
- Close out of Settings and return to the Google Home app
- Reboot your router
- Make sure you power the Chromecast device with the provided power supply into an open electrical outlet, not using a USB input on your TV or other device.
- Check your Apple Wifi settings
- Your Apple device, Chromecast device and Wi-Fi Router should be within ~15 feet (4 meters) of each other.
- Reboot Google Home app on your Apple device > tap on Devices > tap the Cog Wheel > tap on the three stacked dots in the top right corner > tap Reboot
- Conduct a factory data reset on your Chromecast device.
- Try Chromecast on the SAME 2.4 (Chromecast 1st gen requirement) Ghz frequency wifi router band as your iOS devices
- See original post by Google employee about other settings.
