Update CPT Title on Save

Hi. I have a Pod called honey_pot with fields rel_student and rewarded_for. The rel_student field is related to a students pod. I have adapted the following Code from the documentation to update the Title on creating a new post. However, it returns the rel_student post id and not the student name. What am I doing wrong? TIA

add_filter( 'pods_api_pre_save_pod_item_honey_pot', 'slug_set_title', 10, 2);
function slug_set_title($pieces, $is_new_item) {
    //check if is new item, if not return $pieces without making any changes
    if ( ! $is_new_item ) {
        return $pieces;
    }
    //make sure that all three fields are active
    $fields = array( 'post_title', 'rel_student', 'rewarded_for' );
    foreach( $fields as $field ) {
        if ( ! isset( $pieces[ 'fields_active' ][ $field ] ) ) {
            array_push ($pieces[ 'fields_active' ], $field );
        }
    }
    //set variables for fields empty first for saftey's sake
    $student = $rewarded_for= '';
    
	//This returns post id and not the students name.  I need the Students name here
    if ( isset( $pieces[ 'fields' ][ 'rel_student' ] ) && isset( $pieces[ 'fields'][ 'rel_student' ][ 'value' ] ) && is_string( $pieces[ 'fields' ][ 'rel_student' ][ 'value' ] ) ) {
        $student = $pieces[ 'fields' ][ 'rel_student' ][ 'value' ];
    }
    //this works without problem
    if ( isset( $pieces[ 'fields' ][ 'rewarded_for' ] ) && isset( $pieces[ 'fields'][ 'rewarded_for' ][ 'value' ] ) && is_string( $pieces[ 'fields' ][ 'rewarded_for' ][ 'value' ] ) ) {
        $rewarded_for = $pieces[ 'fields' ][ 'rewarded_for' ][ 'value' ];
    }
    //set post title using $student and $rewarded_for
    $pieces[ 'object_fields' ][ 'post_title' ][ 'value' ] = $student . ' for ' . $rewarded_for;
    //return $pieces to save
    return $pieces;
}