sub domain question

[taproot]

I have a site that I only host email and a subdomain for and I do not host the DNS. So to try and set this up I had them create an A record that pointed to the server IP address. Then I created an account for them and setup the mail records in DNS which is all working fine. I added a subdomain through their control panel crm.site.com however if I check that subdomain it comes to the server per the A record and displays the apache default page. The blocks were created in the httpd.conf file and look fine. Any idea why apache cannot resolve the domain correctly? Is it maybe because I have DNS entries from when I setup the account?

I can also get to the correct place by doing the http://serverip/~username and everything is there and working.

Cheers,
TR