Problem with custom domains and subdomains

Let’s say I have a domain called, and a desired subdomain called

I want to use with Okta auth.

I have a CNAME in called that refers to my Okta domain, dev-{number}

I’ve been trying to add to Okta as a custom subdomain, but it keeps failing and I’m not sure why; but it works if I use

I’m just wondering what part of my setup is wrong.

If I run nslookup there’s no response, but yields a response.

Hi @spoiledgoods

Can you please check if the CNAME from is actually pointing to dev-{number} or dev-{number} which is the URL that Okta provides for the DNS entry.

Regarding the issue itself, in your Okta admin panel, can you please go to Settings >> Customization >> Custom URL Domain and check which is the Configured Custom Domain set up, or If you are in Developer Console admin interface, please switch to Classic UI from top left corner.

@dragos Thanks for your reply. My issue here was I totally forgot my domain hosting service adds the base domain onto every CNAME entry; so becomes Kicking myself for suffering from this problem again