Trouble with Google Hangouts and Cookies

I am currently trying to get Google Hangouts to work on an iPhone. The iPhone is using updated software (iOS 10.3.1). I have deleted and reinstalled the app onto the phone. I have set Safari to "enable cookies" always. However, each time I try to get Hangouts to start working, and I enter my email address, I consistently get the message "Your browser has cookies disabled. Make sure your cookies are enabled and try again." I have turned the phone on and off again, and tried repeating the start up for Google Hangouts. Each time, I get the same message. What am I missing? Please help.