Here is the solution:
According to an older locked thread, the solution used to be going to purple.com. After talking to a support rep from Google, I was told to go to neverssl.com or blue.com instead. This worked for me. He told me that they used to instruct people to go to red.com or purple.com. As those have (smartly) switched to a more secure https server, they no longer allow redirects which now causes it to fail.
1. Connect to Google Starbucks on your wifi network
2. Open your Chrome web browser
3. In the URL bar type: neverssl.com or blue.com
4. You will be redirected to a Starbucks screen with a working internet connection.
If for some reason this isn't working for you, you can contact them directly via this support page: https://support.google.com/fiber/answer/3289712?hl=en which includes their phone number: (855) 446-2374.
Good luck!