You are unable to install Symantec Endpoint Protection Manager, (SEPM) on a Core version of Windows 2016/2019. You are prompted when trying to install, "Internet Explorer 6 or greater needs to be installed for this installation to continue".
Release : 14.x
Windows Server Core does not include Internet Explorer, which is required to work.
It is not supported to install SEPM on any version of Windows Core OS
For reference:
System requirements for Symantec Endpoint Protection (SEP) 14.3 RU10