Please try adding this custom code in your wplms-customizer.php file
add_filter('bp_course_get_user_certificates',function($certis,$user_id){
$certificates=get_user_meta($user_id,'certificates',true);
if(!empty($certificates)){
$certis = [];
foreach ($certificates as $key => $c) {
if(!empty(get_permalink($c))){
$certis[]=$c;
}
}
$certificates=$certis;
}
return $certificates;
},99,2);