Your shortcode callback function is incorrect:
add_shortcode('load_peoplesoft_result_page', 'load_peoplesoft_results()');
You’ve included the ()
, but only the function name should be passed:
add_shortcode( 'load_peoplesoft_result_page', 'load_peoplesoft_results' );
Note that the second argument of add_shortcode()
is a “callable”. This is a standard PHP feature, and you can read documentation for them here.