What is a cPanel server's main IP?
The network configuration of the server determines the server's main IP address. The MainIP is not configurable through cPanel. A network administrator or your hosting provider can only modify it. The main IP is the IP address that the kernel selects as the default outbound IP address. For this reason, this is the IP address that the cPanel licensing system uses as the IP address of your server.
The server's main IP should be the same. If you have your network administrator change the network configuration of the server to change the main IP, you should also change the server's main shared IP.