diff --git a/frontend/src/app/core/state/in-app-notifications/in-app-notifications.actions.ts b/frontend/src/app/core/state/in-app-notifications/in-app-notifications.actions.ts
index 1aeda581f9..284b26c560 100644
--- a/frontend/src/app/core/state/in-app-notifications/in-app-notifications.actions.ts
+++ b/frontend/src/app/core/state/in-app-notifications/in-app-notifications.actions.ts
@@ -18,3 +18,8 @@ export const notificationCountIncreased = action(
   '[IAN] The backend sent a notification count that was higher than the last known',
   props<{ origin:string, count:number }>(),
 );
+
+export const centerUpdatedInPlace = action(
+  '[IAN] The notification center updated the notification list without a full page refresh',
+  props<{ origin:string  }>(),
+);
diff --git a/frontend/src/app/features/in-app-notifications/center/menu/menu.component.ts b/frontend/src/app/features/in-app-notifications/center/menu/menu.component.ts
index 56a700c571..33677b28d2 100644
--- a/frontend/src/app/features/in-app-notifications/center/menu/menu.component.ts
+++ b/frontend/src/app/features/in-app-notifications/center/menu/menu.component.ts
@@ -96,7 +96,7 @@ export class IanMenuComponent implements OnInit {
     map(([byProject, byReason]) => [
       ...this.baseMenuItems.map((baseMenuItem) => ({
         ...baseMenuItem,
-        count: byReason.reduce((a, b) => a + (b.count || 0), 0),
+        count: byProject.reduce((a, b) => a + (b.count || 0), 0),
       })),
       {
         title: this.I18n.t('js.notifications.menu.by_reason'),
diff --git a/frontend/src/app/features/in-app-notifications/center/state/ian-center.service.ts b/frontend/src/app/features/in-app-notifications/center/state/ian-center.service.ts
index 011d09947b..69bafdb92b 100644
--- a/frontend/src/app/features/in-app-notifications/center/state/ian-center.service.ts
+++ b/frontend/src/app/features/in-app-notifications/center/state/ian-center.service.ts
@@ -23,6 +23,7 @@ import {
   markNotificationsAsRead,
   notificationsMarkedRead,
   notificationCountIncreased,
+  centerUpdatedInPlace,
 } from 'core-app/core/state/in-app-notifications/in-app-notifications.actions';
 import { InAppNotification } from 'core-app/core/state/in-app-notifications/in-app-notification.model';
 import { IanCenterQuery } from 'core-app/features/in-app-notifications/center/state/ian-center.query';
@@ -186,6 +187,7 @@ export class IanCenterService extends UntilDestroyedMixin {
           text: this.I18n.t('js.notifications.center.new_notifications.link_text'),
           target: () => {
             this.store.update({ activeCollection: collection });
+            this.actions$.dispatch(centerUpdatedInPlace({ origin: this.id }));
           },
         },
       });
diff --git a/frontend/src/app/features/work-packages/routing/wp-view-base/state/wp-single-view.service.ts b/frontend/src/app/features/work-packages/routing/wp-view-base/state/wp-single-view.service.ts
index fcc73b0125..7090ec93e1 100644
--- a/frontend/src/app/features/work-packages/routing/wp-view-base/state/wp-single-view.service.ts
+++ b/frontend/src/app/features/work-packages/routing/wp-view-base/state/wp-single-view.service.ts
@@ -12,6 +12,7 @@ import { ApiV3ListFilter } from 'core-app/core/apiv3/paths/apiv3-list-resource.i
 import {
   markNotificationsAsRead,
   notificationsMarkedRead,
+  centerUpdatedInPlace,
 } from 'core-app/core/state/in-app-notifications/in-app-notifications.actions';
 import { ActionsService } from 'core-app/core/state/actions/actions.service';
 import {
@@ -86,4 +87,12 @@ export class WpSingleViewService {
   private reloadOnNotificationRead() {
     this.reload();
   }
+
+  /**
+   * Reload after notifications were successfully marked as read
+   */
+  @EffectCallback(centerUpdatedInPlace)
+  private reloadOnCenterUpdate() {
+    this.reload();
+  }
 }
diff --git a/frontend/src/global_styles/openproject/_mixins.sass b/frontend/src/global_styles/openproject/_mixins.sass
index a4fe5c898b..22c75b9980 100644
--- a/frontend/src/global_styles/openproject/_mixins.sass
+++ b/frontend/src/global_styles/openproject/_mixins.sass
@@ -265,6 +265,7 @@ $scrollbar-size: 10px
   font-weight: bold
   background: #00A3FF
   color: white
+  flex-shrink: 0
 
 @mixin show-on-focus
   position: absolute