Thanks for reaching out and for being a step ahead of us. Let's check this further.
Is the Chromecast already set up? What's the LED status on your Chromecast device? Could you try to reboot your Wi-Fi router and make sure the devices are close to each other? Also, plug in your Chromecast to a different HDMI port on your TV then test.
Just checking in to make sure that you've seen my response. Please let me know if you still need help or if you have other questions or concerns as I will be locking this in 24 hours. Feel free to start a new thread and we'll be happy to help.