Trouble setting up Subdomain "w" - w.example.com

Hello!

I’m having trouble setting up a subdomain w.example.com. I am able to set up many other types of subdomains - “test.example.com”, “m.example.com”. For whatever reason, I cannot set up w.example.com OR ww.example.com.

I get this error message: “Error message: This Domain already exists as a website. [404]”

Can anyone help me? I really need to set up w.example.com.

I’m getting same error

My guess is that it is related to www. being reserved