YEs we went to check the code at your end but could not understand why this is happening at your end only .
Please try adding this code adn remove the previous one in your wplms customizer plugin :
add_action('wplms_certificate_earned',function(){
$init->certificated_ran = 1;
});
add_action('init',function(){
$init = Wplms_Pdf_Certificates_Init::init();
if(!empty($init->certificated_ran)){
remove_action('wplms_certificate_earned',array($init,'certificate_earned'),999,3);
}
});