MOBILE-4069 book: Fix PTR in book index page

src/addons/mod/book/components/index/index.ts

@@ -60,6 +60,13 @@ export class AddonModBookIndexComponent extends CoreCourseModuleMainResourceComp
         ]);
     }
 
+    /**
+     * @inheritdoc
+     */
+    protected async invalidateContent(): Promise<void> {
+        await AddonModBook.invalidateContent(this.module.id, this.courseId);
+    }
+
     /**
      * Load book data.
      *