Completely new and vanilla CentOS installed using the install script. PHP7.2 and 5.6 both installed per default. PHP -v indicates 5.4 as the version. As I understand it, Webmin should use the newest installed version (7.2 in this case).
In the virtual server domain > server configuration > PHP versions it indicates 7.2.
Oh, that is quite normal. It depends on the distro and other PHP version installed. It might be still possible to change default PHP version on RHEL as well… Look at this thread, I haven’t tested it.
You can always point your app to use PHP binary at choice, at any location, disregard of what is set by default, whether default callable php is a symlink or not.