Patch from @pslaughter

app/assets/javascripts/main.js

@@ -203,10 +203,7 @@ $body.on('ajax:complete, ajax:beforeSend, submit', 'form', function ajaxComplete
 });
 
 $('.navbar-toggler').on('click', () => {
-  // The order is important. The `menu-expanded` is used as a source of truth for now.
-  // This can be simplified when the :combined_menu feature flag is removed.
-  // https://gitlab.com/gitlab-org/gitlab/-/issues/333180
-  navEventHub.$emit(EVENT_RESPONSIVE_TOGGLE);
+  document.body.classList.toggle('top-nav-responsive-open');
 });
 
 /**

app/assets/javascripts/nav/components/responsive_app.vue

@@ -2,8 +2,7 @@
 import { FREQUENT_ITEMS_PROJECTS, FREQUENT_ITEMS_GROUPS } from '~/frequent_items/constants';
 import { BV_DROPDOWN_SHOW, BV_DROPDOWN_HIDE } from '~/lib/utils/constants';
 import KeepAliveSlots from '~/vue_shared/components/keep_alive_slots.vue';
-import eventHub, { EVENT_RESPONSIVE_TOGGLE } from '../event_hub';
-import { resetMenuItemsActive, hasMenuExpanded } from '../utils';
+import { resetMenuItemsActive } from '../utils';
 import ResponsiveHeader from './responsive_header.vue';
 import ResponsiveHome from './responsive_home.vue';
 import TopNavContainerView from './top_nav_container_view.vue';
@@ -33,25 +32,14 @@ export default {
     },
   },
   created() {
-    eventHub.$on(EVENT_RESPONSIVE_TOGGLE, this.updateResponsiveOpen);
     this.$root.$on(BV_DROPDOWN_SHOW, this.showMobileOverlay);
     this.$root.$on(BV_DROPDOWN_HIDE, this.hideMobileOverlay);
-
-    this.updateResponsiveOpen();
   },
   beforeDestroy() {
-    eventHub.$off(EVENT_RESPONSIVE_TOGGLE, this.onToggle);
     this.$root.$off(BV_DROPDOWN_SHOW, this.showMobileOverlay);
     this.$root.$off(BV_DROPDOWN_HIDE, this.hideMobileOverlay);
   },
   methods: {
-    updateResponsiveOpen() {
-      if (hasMenuExpanded()) {
-        document.body.classList.add('top-nav-responsive-open');
-      } else {
-        document.body.classList.remove('top-nav-responsive-open');
-      }
-    },
     onMenuItemClick({ view }) {
       if (view) {
         this.activeView = view;

app/assets/javascripts/nav/event_hub.js

-import eventHubFactory from '~/helpers/event_hub_factory';
-
-export const EVENT_RESPONSIVE_TOGGLE = 'top-nav-responsive-toggle';
-
-export default eventHubFactory();

app/assets/javascripts/nav/utils/has_menu_expanded.js

-export const hasMenuExpanded = () =>
-  Boolean(document.querySelector('.header-content.menu-expanded'));

app/assets/javascripts/nav/utils/index.js

-export * from './has_menu_expanded';
 export * from './reset_menu_items_active';

app/assets/stylesheets/framework/header.scss

@@ -27,17 +27,6 @@ $top-nav-hover-bg: var(--indigo-900-alpha-008, $indigo-900-alpha-008) !important
     display: none;
   }
 
-  .menu-expanded {
-    .more-icon {
-      display: none;
-    }
-
-    .close-icon {
-      display: block;
-      margin: auto;
-    }
-  }
-
   .header-content {
     width: 100%;
     display: flex;
@@ -103,18 +92,6 @@ $top-nav-hover-bg: var(--indigo-900-alpha-008, $indigo-900-alpha-008) !important
     .navbar-collapse > ul.nav > li:not(.d-none) {
       margin: 0 2px;
     }
-
-    &.menu-expanded {
-      @include media-breakpoint-down(xs) {
-        .hide-when-top-nav-responsive-open {
-          display: none;
-        }
-
-        .navbar-collapse {
-          display: flex;
-        }
-      }
-    }
   }
 
   .navbar-collapse {
@@ -673,19 +650,30 @@ $top-nav-hover-bg: var(--indigo-900-alpha-008, $indigo-900-alpha-008) !important
 }
 
 .top-nav-responsive-open {
-  .hide-when-top-nav-responsive-open {
-    @include media-breakpoint-down(xs) {
+  .more-icon {
+    display: none;
+  }
+
+  .close-icon {
+    display: block;
+    margin: auto;
+  }
+
+  @include media-breakpoint-down(xs) {
+    .navbar-collapse {
+      display: flex;
+    }
+
+    .hide-when-top-nav-responsive-open {
       display: none !important;
     }
-  }
 
-  .top-nav-responsive {
-    @include media-breakpoint-down(xs) {
+    .top-nav-responsive {
       @include gl-display-block;
     }
-  }
 
-  .navbar-gitlab .header-content .title-container {
-    flex: 0;
+    .navbar-gitlab .header-content .title-container {
+      flex: 0;
+    }
   }
 }