We have a public facing server that is inaccessible from an internal network(DNS name: 123.net). Switching to a different network with different DNS 123.com there's no problem connecting or even accessing it outside our network. Server is using DNS 123.com.
Nslookup is pointed to correct ip address from a device that uses DNS123.net. Nslookup from internal network using DNS 123.com points to correct internal IP address.