Thanks for posting here in the Google Nest Community.
I know how it feels when something isn’t working as it should. A few things: are you using a dual band router? If so, which band are you using 2.4 Ghz or 5 Ghz? Is your phone on the same band? What is the make and model of the mobile phone that you are using? Is this how you are doing the reset?
You can uninstall and reinstall your Google Home app. Rebooting your phone, Chromecast and Wi-Fi router might help to refresh your devices and signal.
Let me know how it goes.
@swgalley, thanks for the help.
@CarSars, I'm chiming in to ensure you've got the answer you're looking for. Have you already tried the factory reset? Doing so will revert your devices back to its default and original settings. Open the link above.
Feel free to let us know if you have more questions about this.