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 a8a136c8e0a..85e0f5b1860 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
@@ -634,7 +634,12 @@ odoo.define('website_slides.fullscreen', function (require) {
                 return self._renderSlide();
             }).then(function() {
                 if (slide._autoSetDone && !session.is_website_user) {  // no useless RPC call
-                    return self._setCompleted(slide.id);
+                    if (['document', 'presentation'].includes(slide.type)) {
+                        // only set the slide as completed after iFrame is loaded to avoid concurrent execution with 'embedUrl' controller
+                        self.el.querySelector('iframe.o_wslides_iframe_viewer').addEventListener('load', () => self._setCompleted(slide.id));
+                    } else {
+                           return self._setCompleted(slide.id);
+                    }
                 }
             });
         },
diff --git a/addons/website_slides/static/src/tests/tours/slides_course_member.js b/addons/website_slides/static/src/tests/tours/slides_course_member.js
index 8a7e3076a87..7f30b9456a7 100644
--- a/addons/website_slides/static/src/tests/tours/slides_course_member.js
+++ b/addons/website_slides/static/src/tests/tours/slides_course_member.js
@@ -47,7 +47,7 @@ tour.register('course_member', {
     }
 }, {
     trigger: '.o_wslides_fs_sidebar_header.navigation-success-1',
-    extra_trigger: '.o_wslides_progress_percentage:contains("20")',
+    extra_trigger: '.o_wslides_progress_percentage:contains("40")',
     run: function () {
         // check navigation with arrow keys
         var event = jQuery.Event("keydown");