Subdomains on Cloudflare and Heroku

I have setup a cname for to be an alias of and it works. However, cname for as an alias of does not work.

It does not work with either grey or orange cloud and having clicked on the " I am done " button. Any ideas?


I don’t use Heroku, but the hosting server should be configured for specific CNAMEs to work.

Is Heroku configured to recognize your subdomain using a CNAME for app2?