Additional info:
I set up CNAME entries for each subdomain (mail,calendar,drive,groups,sites) pointing to ghs.googlehosted.com. I tried both proxied and DNS-Only. Neither worked.
I have a SSL certificate uploaded on Google Cloud Console for the subdomains as instructed in the link I referred to above.
I received the following from Google Workspace support:
I have reviewed the details of your account and have determined that the CNAME records which have been added for the subdomains are not propagating across the internet. As our scope of support is limited to Google Workspace, we are unable to provide support for issues related to DNS. Therefore, I kindly request that you contact the DNS provider associated with your domain for further assistance in resolving this matter.
It’s best to start with all DNS records set to DNS-Only, and make sure it’s all working correctly with HTTPS. Then you can proxy it, and it should work.
When you say “google apps”, do you mean a custom Google App Engine app, or native Google Workspace apps (Gmail, Calendar, Docs, Groups, and Sites)?
And instead of the 3rd-party instructions, what specific official instructions from Google are you following to add your custom domain? Can you share a public URL or screenshot from the setup wizard showing the DNS record(s) that Google said you should add?
The screenshows below are instructions I got from Google’s setup wizards when I tried adding custom domains to a Google App Engine app and Google Workspace respectively. Did you get to either of these screens in your setup to actually activate the custom domain?
It seems to me you have some unfinished business in your Google dashboard.
I have tried both methods (Google Apps Engine and Google Workspace Apps). Let me try to clarify what it is I am attempting to accomplish:
I use Cloudflare as my domain registrar.
I have my own domain (5-scotts{dot}com)
I host a very simple weather website on the root of my domain (self-hosted).
I have several subdomains that I point to other areas on my host server. (e.q. weathercam{dot}5-scotts{dot}com will take you to my weather webcam page.
I would like to have a subdomain for each of the Google Workspace Apps so that mail{dot}5-scotts{dot}com would take you to the GMail site, calendar.5-scotts.com would take to to google calendar, etc… . Ideally would like those be ‘proxied’ as opposed to being redirected, if that is possible. Also would prefer those to be HTTPS:// not HTTP://, if that is possible.
I have two Google Sites that I would like subdomains to point to. I have custom URLS setup in the google site so that matthew{dot}5-scotts{dot}com should take me to mt google sites page for that. (again preferred it be proxied and not redirected and HTTPS:// no HTTP://)
I have tried many, many setups and I admit I may be mixing Google Apps Engine and Google Workspace setups incorrectly. I was able to get redirection to HTTP:// to work, but that is my least favored option, so I am looking to see if the more preferred option can work (proxying and HTTPS://) for the subdomains that are on google assets.
If all your relevant DNS records are DNS-Only, your next step would be to get help from Google Support, so they can tell you what’s wrong with your configuration.