Cannot Resolve Hostname

So i got a new ip for my minecraft server from godaddy and it doesnt work,
Ex:

Original IP: server.mcpro.co
New IP: mc.server.ca
If i put the server port at the end of the new ip, it works. If i dont it says
"Cannot Resolve Hostname"
Also the other owner can use mc.server.ca without the port.

(Server is not my real servers name)