Domain Mapping health invalid

So, I have enabled the domain mapping plugin at
I have created a fresh install on a subdomain,
I have created a mapping for to that subdomain
I have created a A record with the registrar that points the domain to our server's IP address.
In the domain mapping dashboard the A record seems to be showing up, but the health status is listed as invalid, and the domain doesn't actually resolve to that install.

I'm not sure where to go at this point....