diff --git a/app/assets/javascripts/discourse/app/components/discovery/categories-display.gjs b/app/assets/javascripts/discourse/app/components/discovery/categories-display.gjs
index 4cccf7712bd..6a9ccd8b24a 100644
--- a/app/assets/javascripts/discourse/app/components/discovery/categories-display.gjs
+++ b/app/assets/javascripts/discourse/app/components/discovery/categories-display.gjs
@@ -75,14 +75,21 @@ export default class CategoriesDisplay extends Component {
     }
   }
 
+  get canLoadMore() {
+    return this.siteSettings.lazy_load_categories && this.args.loadMore;
+  }
+
   <template>
     <PluginOutlet
       @name="above-discovery-categories"
       @connectorTagName="div"
       @outletArgs={{hash categories=@categories topics=@topics}}
     />
-    {{#if this.siteSettings.lazy_load_categories}}
-      <LoadMore @selector=".category" @action={{@loadMore}}>
+    {{#if this.canLoadMore}}
+      <LoadMore
+        @selector=".category:not(.muted-categories *)"
+        @action={{@loadMore}}
+      >
         <this.categoriesComponent
           @categories={{@categories}}
           @topics={{@topics}}
diff --git a/app/assets/javascripts/discourse/app/models/category-list.js b/app/assets/javascripts/discourse/app/models/category-list.js
index 22c7ee205c5..2311eed3a7c 100644
--- a/app/assets/javascripts/discourse/app/models/category-list.js
+++ b/app/assets/javascripts/discourse/app/models/category-list.js
@@ -1,5 +1,4 @@
 import ArrayProxy from "@ember/array/proxy";
-import EmberObject from "@ember/object";
 import { ajax } from "discourse/lib/ajax";
 import { number } from "discourse/lib/formatter";
 import PreloadStore from "discourse/lib/preload-store";
@@ -9,83 +8,79 @@ import Topic from "discourse/models/topic";
 import { bind } from "discourse-common/utils/decorators";
 import I18n from "discourse-i18n";
 
-const MAX_CATEGORIES_LIMIT = 25;
-
 const CategoryList = ArrayProxy.extend({
   init() {
+    this.set("content", this.categories || []);
     this._super(...arguments);
-    this.set("content", []);
     this.set("page", 1);
+    this.set("fetchedLastPage", false);
   },
 
   @bind
   async loadMore() {
-    if (this.isLoading || this.lastPage) {
+    if (this.isLoading || this.fetchedLastPage) {
       return;
     }
 
     this.set("isLoading", true);
 
-    const data = { page: this.page + 1, limit: MAX_CATEGORIES_LIMIT };
-    if (this.parentCategory) {
-      data.parent_category_id = this.parentCategory.id;
-    }
+    const data = { page: this.page + 1 };
     const result = await ajax("/categories.json", { data });
+
     this.set("page", data.page);
-
-    result.category_list.categories.forEach((c) => {
-      const record = Site.current().updateCategory(c);
-      this.categories.pushObject(record);
-    });
-
+    if (result.category_list.categories.length === 0) {
+      this.set("fetchedLastPage", true);
+    }
     this.set("isLoading", false);
 
-    if (result.category_list.categories.length === 0) {
-      this.set("lastPage", true);
-    }
-
     const newCategoryList = CategoryList.categoriesFrom(this.store, result);
-    this.categories.pushObjects(newCategoryList.categories);
+    newCategoryList.forEach((c) => this.categories.pushObject(c));
   },
 });
 
 CategoryList.reopenClass({
-  categoriesFrom(store, result) {
-    const categories = CategoryList.create({ store });
-    const list = Category.list();
-
-    let statPeriod = "all";
-    const minCategories = result.category_list.categories.length * 0.66;
-
-    ["week", "month"].some((period) => {
-      const filteredCategories = result.category_list.categories.filter(
-        (c) => c[`topics_${period}`] > 0
-      );
-      if (filteredCategories.length >= minCategories) {
-        statPeriod = period;
-        return true;
-      }
-    });
+  categoriesFrom(store, result, parentCategory = null) {
+    // Find the period that is most relevant
+    const statPeriod =
+      ["week", "month"].find(
+        (period) =>
+          result.category_list.categories.filter(
+            (c) => c[`topics_${period}`] > 0
+          ).length >=
+          result.category_list.categories.length * 0.66
+      ) || "all";
 
+    // Update global category list to make sure that `findById` works as
+    // expected later
     result.category_list.categories.forEach((c) =>
-      categories.pushObject(this._buildCategoryResult(c, list, statPeriod))
+      Site.current().updateCategory(c)
     );
 
+    const categories = CategoryList.create({ store });
+    result.category_list.categories.forEach((c) => {
+      c = this._buildCategoryResult(c, statPeriod);
+      if (
+        !c.parent_category_id ||
+        c.parent_category_id === parentCategory?.id
+      ) {
+        categories.pushObject(c);
+      }
+    });
     return categories;
   },
 
-  _buildCategoryResult(c, list, statPeriod) {
+  _buildCategoryResult(c, statPeriod) {
     if (c.parent_category_id) {
-      c.parentCategory = list.findBy("id", c.parent_category_id);
+      c.parentCategory = Category.findById(c.parent_category_id);
     }
 
     if (c.subcategory_list) {
       c.subcategories = c.subcategory_list.map((subCategory) =>
-        this._buildCategoryResult(subCategory, list, statPeriod)
+        this._buildCategoryResult(subCategory, statPeriod)
       );
     } else if (c.subcategory_ids) {
-      c.subcategories = c.subcategory_ids.map((scid) =>
-        list.findBy("id", parseInt(scid, 10))
+      c.subcategories = c.subcategory_ids.map((subCategoryId) =>
+        Category.findById(parseInt(subCategoryId, 10))
       );
     }
 
@@ -99,7 +94,6 @@ CategoryList.reopenClass({
     }
 
     const stat = c[`topics_${statPeriod}`];
-
     if ((statPeriod === "week" || statPeriod === "month") && stat > 0) {
       const unit = I18n.t(`categories.topic_stat_unit.${statPeriod}`);
 
@@ -122,7 +116,7 @@ CategoryList.reopenClass({
       c.pickAll = true;
     }
 
-    if (Site.currentProp("mobileView")) {
+    if (Site.current().mobileView) {
       c.statTotal = I18n.t("categories.topic_stat_all_time", {
         count: c.topics_all_time,
         number: `<span class="value">${number(c.topics_all_time)}</span>`,
@@ -137,26 +131,25 @@ CategoryList.reopenClass({
   listForParent(store, category) {
     return ajax(
       `/categories.json?parent_category_id=${category.get("id")}`
-    ).then((result) => {
-      return EmberObject.create({
+    ).then((result) =>
+      CategoryList.create({
         store,
-        categories: this.categoriesFrom(store, result),
+        categories: this.categoriesFrom(store, result, category),
         parentCategory: category,
-      });
-    });
+      })
+    );
   },
 
   list(store) {
-    const getCategories = () => ajax("/categories.json");
-    return PreloadStore.getAndRemove("categories_list", getCategories).then(
-      (result) => {
-        return CategoryList.create({
-          store,
-          categories: this.categoriesFrom(store, result),
-          can_create_category: result.category_list.can_create_category,
-          can_create_topic: result.category_list.can_create_topic,
-        });
-      }
+    return PreloadStore.getAndRemove("categories_list", () =>
+      ajax("/categories.json")
+    ).then((result) =>
+      CategoryList.create({
+        store,
+        categories: this.categoriesFrom(store, result),
+        can_create_category: result.category_list.can_create_category,
+        can_create_topic: result.category_list.can_create_topic,
+      })
     );
   },
 });
diff --git a/app/assets/javascripts/discourse/app/models/category.js b/app/assets/javascripts/discourse/app/models/category.js
index 1308c539f42..6bd2bea61fb 100644
--- a/app/assets/javascripts/discourse/app/models/category.js
+++ b/app/assets/javascripts/discourse/app/models/category.js
@@ -78,9 +78,9 @@ const Category = RestModel.extend({
     }
   },
 
-  @discourseComputed("subcategories")
-  isParent(subcategories) {
-    return subcategories && subcategories.length > 0;
+  @discourseComputed("has_children", "subcategories")
+  isParent(hasChildren, subcategories) {
+    return hasChildren || (subcategories && subcategories.length > 0);
   },
 
   @discourseComputed("subcategories")
diff --git a/app/assets/javascripts/discourse/app/models/site.js b/app/assets/javascripts/discourse/app/models/site.js
index 9d071d1c64d..fadcda4541f 100644
--- a/app/assets/javascripts/discourse/app/models/site.js
+++ b/app/assets/javascripts/discourse/app/models/site.js
@@ -128,6 +128,16 @@ const Site = RestModel.extend({
         "parentCategory",
         this.categoriesById[newCategory.parent_category_id]
       );
+      newCategory.set(
+        "subcategories",
+        this.categories.filterBy("parent_category_id", categoryId)
+      );
+      if (newCategory.parentCategory) {
+        if (!newCategory.parentCategory.subcategories) {
+          newCategory.parentCategory.set("subcategories", []);
+        }
+        newCategory.parentCategory.subcategories.pushObject(newCategory);
+      }
       return newCategory;
     }
   },
diff --git a/app/models/category_list.rb b/app/models/category_list.rb
index 1baad99f283..6240256c265 100644
--- a/app/models/category_list.rb
+++ b/app/models/category_list.rb
@@ -156,7 +156,15 @@ class CategoryList
     notification_levels = CategoryUser.notification_levels_for(@guardian.user)
     default_notification_level = CategoryUser.default_notification_level
 
-    if @options[:parent_category_id].blank?
+    if SiteSetting.lazy_load_categories
+      subcategory_ids = {}
+      Category
+        .secured(@guardian)
+        .where(parent_category_id: @categories.map(&:id))
+        .pluck(:id, :parent_category_id)
+        .each { |id, parent_id| (subcategory_ids[parent_id] ||= []) << id }
+      @categories.each { |c| c.subcategory_ids = subcategory_ids[c.id] || [] }
+    elsif @options[:parent_category_id].blank?
       subcategory_ids = {}
       subcategory_list = {}
       to_delete = Set.new
diff --git a/spec/models/category_list_spec.rb b/spec/models/category_list_spec.rb
index ec3a46de1ed..94e33058ef8 100644
--- a/spec/models/category_list_spec.rb
+++ b/spec/models/category_list_spec.rb
@@ -374,4 +374,18 @@ RSpec.describe CategoryList do
       expect(category_list.categories[-1].custom_field_preloaded?("bob")).to be_falsey
     end
   end
+
+  describe "lazy_load_categories" do
+    fab!(:category) { Fabricate(:category, user: admin) }
+    fab!(:subcategory) { Fabricate(:category, user: admin, parent_category: category) }
+
+    before { SiteSetting.lazy_load_categories = true }
+
+    it "returns categories with subcategory_ids" do
+      expect(category_list.categories.size).to eq(3)
+      expect(
+        category_list.categories.find { |c| c.id == category.id }.subcategory_ids,
+      ).to contain_exactly(subcategory.id)
+    end
+  end
 end