diff --git a/app/assets/javascripts/discourse/app/controllers/preferences/categories.js b/app/assets/javascripts/discourse/app/controllers/preferences/categories.js
index 16555cdad91..3611af258f9 100644
--- a/app/assets/javascripts/discourse/app/controllers/preferences/categories.js
+++ b/app/assets/javascripts/discourse/app/controllers/preferences/categories.js
@@ -4,26 +4,41 @@ import { or } from "@ember/object/computed";
 import { popupAjaxError } from "discourse/lib/ajax-error";
 
 export default Controller.extend({
-  init() {
-    this._super(...arguments);
-
-    this.saveAttrNames = [
-      "muted_category_ids",
-      "regular_category_ids",
+  @discourseComputed("siteSettings.mute_all_categories_by_default")
+  saveAttrNames(muteAllCategoriesByDefault) {
+    return [
       "watched_category_ids",
       "tracked_category_ids",
       "watched_first_post_category_ids",
+      muteAllCategoriesByDefault
+        ? "regular_category_ids"
+        : "muted_category_ids",
     ];
   },
 
   @discourseComputed(
+    "siteSettings.mute_all_categories_by_default",
     "model.watchedCategories",
     "model.watchedFirstPostCategories",
     "model.trackedCategories",
-    "model.mutedCategories"
+    "model.mutedCategories",
+    "model.regularCategories"
   )
-  selectedCategories(watched, watchedFirst, tracked, muted) {
-    return [].concat(watched, watchedFirst, tracked, muted).filter((t) => t);
+  selectedCategories(
+    muteAllCategoriesByDefault,
+    watched,
+    watchedFirst,
+    tracked,
+    muted,
+    regular
+  ) {
+    let categories = [].concat(watched, watchedFirst, tracked);
+
+    categories = categories.concat(
+      muteAllCategoriesByDefault ? regular : muted
+    );
+
+    return categories.filter((t) => t);
   },
 
   @discourseComputed
diff --git a/app/assets/javascripts/discourse/app/models/user.js b/app/assets/javascripts/discourse/app/models/user.js
index 80b093c568b..6be7b0398fa 100644
--- a/app/assets/javascripts/discourse/app/models/user.js
+++ b/app/assets/javascripts/discourse/app/models/user.js
@@ -398,22 +398,28 @@ const User = RestModel.extend({
     let updatedState = {};
 
     ["muted", "regular", "watched", "tracked", "watched_first_post"].forEach(
-      (s) => {
-        if (fields === undefined || fields.includes(s + "_category_ids")) {
+      (categoryNotificationLevel) => {
+        if (
+          fields === undefined ||
+          fields.includes(`${categoryNotificationLevel}_category_ids`)
+        ) {
           let prop =
-            s === "watched_first_post"
+            categoryNotificationLevel === "watched_first_post"
               ? "watchedFirstPostCategories"
-              : s + "Categories";
+              : `${categoryNotificationLevel}Categories`;
+
           let cats = this.get(prop);
+
           if (cats) {
             let cat_ids = cats.map((c) => c.get("id"));
-            updatedState[s + "_category_ids"] = cat_ids;
+            updatedState[`${categoryNotificationLevel}_category_ids`] = cat_ids;
 
             // HACK: denote lack of categories
             if (cats.length === 0) {
               cat_ids = [-1];
             }
-            data[s + "_category_ids"] = cat_ids;
+
+            data[`${categoryNotificationLevel}_category_ids`] = cat_ids;
           }
         }
       }
diff --git a/app/assets/javascripts/discourse/app/templates/preferences/categories.hbs b/app/assets/javascripts/discourse/app/templates/preferences/categories.hbs
index ac28c0b2cec..8a0b2b716b3 100644
--- a/app/assets/javascripts/discourse/app/templates/preferences/categories.hbs
+++ b/app/assets/javascripts/discourse/app/templates/preferences/categories.hbs
@@ -1,7 +1,7 @@
 <div class="control-group category-notifications">
   <label class="control-label">{{i18n "user.categories_settings"}}</label>
 
-  <div class="controls tracking-controls">
+  <div class="controls tracking-controls tracking-controls--watched-categories">
     <label>{{d-icon "d-watching"}} {{i18n "user.watched_categories"}}</label>
     {{#if this.canSee}}
       <a class="show-tracking" href={{this.model.watchingTopicsPath}}>{{i18n "user.tracked_topics_link"}}</a>
@@ -10,7 +10,7 @@
   </div>
   <div class="instructions">{{i18n "user.watched_categories_instructions"}}</div>
 
-  <div class="controls tracking-controls">
+  <div class="controls tracking-controls tracking-controls--tracked-categories">
     <label>{{d-icon "d-tracking"}} {{i18n "user.tracked_categories"}}</label>
     {{#if this.canSee}}
       <a class="show-tracking" href={{this.model.trackingTopicsPath}}>{{i18n "user.tracked_topics_link"}}</a>
@@ -19,20 +19,20 @@
   </div>
   <div class="instructions">{{i18n "user.tracked_categories_instructions"}}</div>
 
-  <div class="controls tracking-controls">
+  <div class="controls tracking-controls tracking-controls--watched-first-categories">
     <label>{{d-icon "d-watching-first"}} {{i18n "user.watched_first_post_categories"}}</label>
     <CategorySelector @categories={{this.model.watchedFirstPostCategories}} @blockedCategories={{this.selectedCategories}} @onChange={{action (mut this.model.watchedFirstPostCategories)}} />
   </div>
   <div class="instructions">{{i18n "user.watched_first_post_categories_instructions"}}</div>
 
   {{#if this.siteSettings.mute_all_categories_by_default}}
-    <div class="controls tracking-controls">
+    <div class="controls tracking-controls tracking-controls--regular-categories">
       <label>{{d-icon "d-regular"}} {{i18n "user.regular_categories"}}</label>
       <CategorySelector @categories={{this.model.regularCategories}} @blockedCategories={{this.selectedCategories}} @onChange={{action (mut this.model.regularCategories)}} />
     </div>
     <div class="instructions">{{i18n "user.regular_categories_instructions"}}</div>
   {{else}}
-    <div class="controls tracking-controls">
+    <div class="controls tracking-controls tracking-controls--muted-categories">
       <label>{{d-icon "d-muted"}} {{i18n "user.muted_categories"}}</label>
       {{#if this.canSee}}
         <a class="show-tracking" href={{this.model.mutedTopicsPath}}>{{i18n "user.tracked_topics_link"}}</a>
diff --git a/app/assets/javascripts/discourse/tests/acceptance/user-preferences-categories-test.js b/app/assets/javascripts/discourse/tests/acceptance/user-preferences-categories-test.js
new file mode 100644
index 00000000000..2674921aae6
--- /dev/null
+++ b/app/assets/javascripts/discourse/tests/acceptance/user-preferences-categories-test.js
@@ -0,0 +1,75 @@
+import { test } from "qunit";
+import { click, visit } from "@ember/test-helpers";
+import { acceptance } from "discourse/tests/helpers/qunit-helpers";
+import selectKit from "discourse/tests/helpers/select-kit-helper";
+
+acceptance("User Preferences - Categories", function (needs) {
+  needs.user();
+
+  let putRequestData;
+
+  needs.pretender((server, helper) => {
+    server.put("/u/eviltrout.json", (request) => {
+      putRequestData = helper.parsePostData(request.requestBody);
+      return helper.response({ user: {} });
+    });
+  });
+
+  needs.hooks.afterEach(() => {
+    putRequestData = null;
+  });
+
+  test("tracking category which is set to regular notification level for user when mute_all_categories_by_default site setting is enabled", async function (assert) {
+    this.siteSettings.mute_all_categories_by_default = true;
+
+    await visit("/u/eviltrout/preferences/categories");
+
+    const trackedCategoriesSelector = selectKit(
+      ".tracking-controls--tracked-categories .category-selector"
+    );
+
+    await trackedCategoriesSelector.expand();
+
+    assert.notOk(
+      trackedCategoriesSelector.rowByValue("4").exists(),
+      "category that is set to regular is not available for selection"
+    );
+
+    const regularCategoriesSelector = selectKit(
+      ".tracking-controls--regular-categories .category-selector"
+    );
+
+    await regularCategoriesSelector.expand();
+    await regularCategoriesSelector.deselectItemByValue("4");
+    await trackedCategoriesSelector.expand();
+    await trackedCategoriesSelector.selectRowByValue("4");
+    await click(".save-changes");
+
+    assert.deepEqual(putRequestData, {
+      "regular_category_ids[]": ["-1"],
+      "tracked_category_ids[]": ["4"],
+      "watched_category_ids[]": ["3"],
+      "watched_first_post_category_ids[]": ["-1"],
+    });
+  });
+
+  test("tracking category which is set to regular notification level for user when mute_all_categories_by_default site setting is disabled", async function (assert) {
+    await visit("/u/eviltrout/preferences/categories");
+
+    const categorySelector = selectKit(
+      ".tracking-controls--tracked-categories .category-selector"
+    );
+
+    await categorySelector.expand();
+    // User has `regular_category_ids` set to [4] in fixtures
+    await categorySelector.selectRowByValue(4);
+    await click(".save-changes");
+
+    assert.deepEqual(putRequestData, {
+      "muted_category_ids[]": ["-1"],
+      "tracked_category_ids[]": ["4"],
+      "watched_category_ids[]": ["3"],
+      "watched_first_post_category_ids[]": ["-1"],
+    });
+  });
+});