I hate to ask, but I need to, as its a common issue with chromecasts. When you say you factory reset it, did you follow all the steps on this link?
Chromecasts do not handle network changes well, and unless the factory reset is completed, when you plug it into the tv and turn it on, it needs to be at initial setup, otherwise nothing will work on it. Once the Factory reset is complete, you will plug it into the tv and turn it on, and use your google home app to proceed to set up the chromecast.
First, thank you Ashepherdson for helping answer this question. I appreciate your help!
Hello pastormcolon, thanks for your update. I am glad to hear that your issue has been resolved! I will now go ahead and lock this thread. As always, if you have any new questions or concerns, feel free to make a new post. Have a nice day.