Login to WHM.
In search box look for Networking setup.

Click on the option Change hostname.
In change hostname option type your expected hostname under the new hostname.
Click on Change option to save.
In search box look for Networking setup.

Click on the option Change hostname.
In change hostname option type your expected hostname under the new hostname.
Click on Change option to save.
Updated on: 22 / 10 / 2021