I recently launched a Rails app on Heroku, and used a domain registered through Google Domains. The custom URL loads the site on all devices and computers that I've tried, except for Android devices running KitKat. On KitKat devices, I get a "ERR_NAME_NOT_RESOLVED" error. If I use the heroku url, the site loads on all devices including KitKat, which leads me to believe it's a Google Domains related issue. My domain is associated to the heroku site via CNAME record. Any ideas? Already put in a ticket with Google support, but they've had no luck so far. Thanks.
The question was resolved by Google Domains tech support after three days. It seems that when adding a CNAME record on Google Domains, you must remove the http:// before your app's domain. You must also put a period at the end of your heroku app domain, so "http://arcane-whatever-4322.herokuapp.com" would need to be "arcane-whatever-4322.herokuapp.com." . Google Domains directions are still a little unclear, probably because it's in beta.