Cname forward not working

I am trying to forward a domain I am using for MIAB to our existing website but it keeps pointing to MIAB
I used the custom dns settings and left the subdomain blank

I set the cname to

You can’t CNAME a domain used for mail, actually, because that would redirect all of the DNS records for the domain including the ones for mail to another domain that wouldn’t be configured properly for your box’s mail functions. Only subdomains that aren’t used for mail can have a CNAME record. The more general rule is that CNAME can’t be combined with other DNS records on the same (sub)domain.

… You would have to use A/AAAA records instead.

if I am using a shared IP on the other hosted domain what are my options?

Could you elaborate what it is exactly that you wish to accomplish?? It is not overly clear, thanks!