Tutor LMS - Hide the content as well as the topic list for password protected course. So, go to wp-content/plugins/tutor/templates/single-course.php file and then replace all the code by this gist code.

single-course.php

<?php
/**
 * Template for displaying single course
 *
 * @since v.1.0.0
 *
 * @author Themeum
 * @url https://themeum.com
 *
 * @package TutorLMS/Templates
 * @version 1.4.3
 */

get_header();

do_action('tutor_course/single/before/wrap'); 
?>

<div <?php tutor_post_class('tutor-full-width-course-top tutor-course-top-info tutor-page-wrap'); ?>>
    <div class="tutor-container">
        <div class="tutor-row">
            <div class="tutor-col-8 tutor-col-md-100">
	        <?php do_action('tutor_course/single/before/inner-wrap'); ?>
	        <?php tutor_course_lead_info(); ?>
                <?php if ( ! post_password_required() ) : ?>
	            <?php tutor_course_content(); ?>
	            <?php tutor_course_benefits_html(); ?>
	            <?php tutor_course_topics(); ?>
                <?php else : ?>
                    <?php echo get_the_password_form(); ?>
                <?php endif; ?>
                <?php tutor_course_instructors_html(); ?>
                <?php tutor_course_target_reviews_html(); ?>
	            <?php do_action('tutor_course/single/after/inner-wrap'); ?>
            </div> <!-- .tutor-col-8 -->

            <div class="tutor-col-4">
                <div class="tutor-single-course-sidebar">
                    <?php do_action('tutor_course/single/before/sidebar'); ?>
                    <?php tutor_course_enroll_box(); ?>
                    <?php tutor_course_requirements_html(); ?>
                    <?php tutor_course_tags_html(); ?>
                    <?php tutor_course_target_audience_html(); ?>
                    <?php do_action('tutor_course/single/after/sidebar'); ?>
                </div>
            </div>
        </div>
    </div>
</div>

<?php do_action('tutor_course/single/after/wrap'); ?>

<?php
get_footer();