Domain Mapping with HostGator Nameserver

Have a multisite network using subdomains. Currently, domain mapping is working wonderfully for many of the sites on the network. However, I have built a site at and am trying to use domain mapping to change it to They purchased the domain through, are using a HostGator nameserver and I have added an A record to point to my IP - When I try to go to the site's frontend, I get ERR_NAME_RESOLUTION_FAILED. I have checked the DNS propagation and it looks good, so I am at a loss.