diff --git a/addons/website_slides/static/src/js/slides_course_fullscreen_player.js b/addons/website_slides/static/src/js/slides_course_fullscreen_player.js
index 784c0e57913..91ff6bdac5d 100644
--- a/addons/website_slides/static/src/js/slides_course_fullscreen_player.js
+++ b/addons/website_slides/static/src/js/slides_course_fullscreen_player.js
@@ -5,6 +5,7 @@ odoo.define('website_slides.fullscreen', function (require) {
     var sAnimations = require('website.content.snippets.animation');
     var Widget = require('web.Widget');
     var core = require('web.core');
+    var config = require('web.config');
     var QWeb = core.qweb;
 
     var session = require('web.session');
@@ -321,6 +322,9 @@ odoo.define('website_slides.fullscreen', function (require) {
         start: function (){
             var self = this;
             this.on('change:slide', this, this._onChangeSlide);
+            if  (config.device.size_class > config.device.SIZES.MD) {
+                this._toggleSidebar();
+            }
             return this._super.apply(this, arguments).then(function () {
                 self._onChangeSlide(); // trigger manually once DOM ready, since slide content is not rendered server side
             });
@@ -540,12 +544,20 @@ odoo.define('website_slides.fullscreen', function (require) {
             this.sidebar.goNext();
         },
         /**
-         * Show or Hide the sidebar
+         * Called when the sidebar toggle is clicked -> toggles the sidebar visibility.
          *
          * @private
          */
         _onClickToggleSidebar: function (ev){
             ev.preventDefault();
+            this._toggleSidebar();
+        },
+        /**
+         * Toggles sidebar visibility.
+         *
+         * @private
+         */
+        _toggleSidebar: function () {
             this.$('.o_wslides_fs_sidebar').toggleClass('o_wslides_fs_sidebar_hidden');
             this.$('.o_wslides_fs_toggle_sidebar').toggleClass('active');
         },
diff --git a/addons/website_slides/views/website_slides_templates_lesson_fullscreen.xml b/addons/website_slides/views/website_slides_templates_lesson_fullscreen.xml
index 5180385f117..7b44aff0cda 100644
--- a/addons/website_slides/views/website_slides_templates_lesson_fullscreen.xml
+++ b/addons/website_slides/views/website_slides_templates_lesson_fullscreen.xml
@@ -8,7 +8,7 @@
 
             <div class="o_wslides_slide_fs_header d-flex flex-shrink-0 text-white">
                 <div class="d-flex">
-                    <a class="o_wslides_fs_toggle_sidebar d-flex align-items-center px-3 active" href="#" title="Lessons">
+                    <a class="o_wslides_fs_toggle_sidebar d-flex align-items-center px-3" href="#" title="Lessons">
                         <i class="fa fa-bars"/><span class="d-none d-md-inline-block ml-1">Lessons</span>
                     </a>
                     <a class="o_wslides_fs_review d-flex align-items-center px-3" t-att-href="slide.channel_id.website_url" title="Reviews" t-if="slide.channel_id.allow_comment">
@@ -28,7 +28,7 @@
             <div class="o_wslides_fs_container d-flex position-relative overflow-hidden flex-grow-1">
                 <div class="o_wslides_fs_content align-items-stretch justify-content-center d-flex flex-grow-1 order-2"></div>
 
-                <div class="o_wslides_fs_sidebar text-white flex-shrink-0 order-1">
+                <div class="o_wslides_fs_sidebar o_wslides_fs_sidebar_hidden text-white flex-shrink-0 order-1">
                     <div class="o_wslides_fs_sidebar_content d-flex flex-column px-3 pt-3 h-100">
                         <div class="o_wslides_fs_sidebar_header mb-3">
                             <a class="h5 d-block mb-1" t-attf-href="/slides/#{slug(slide.channel_id)}">