I couldn’t find much documentation on this from other sources, so hopefully this will help someone else. If you ever need to re-ip a windows DHCP server and they are reporting the wrong address in the DHCP manager do the following (from an elevated/administrative command prompt.) At no point did the DHCP server seem to stop serving IPs, it looks like it was really just displaying the wrong IP.

 netsh dhcp delete server  <FQDN> <Old IP Address>
 netsh dhcp add server <FQDN> <New  IP Address>

Changes will replicate across your domain.