diff --git a/Gemfile.lock b/Gemfile.lock
index c7ba18e39b..4df7bbaf13 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -385,7 +385,7 @@ GEM
       json-schema (>= 2.2, < 4.0)
       railties (>= 3.1, < 7.1)
       rspec-core (>= 2.14)
-    rubocop (1.39.0)
+    rubocop (1.40.0)
       json (~> 2.3)
       parallel (~> 1.10)
       parser (>= 3.1.2.1)
diff --git a/app/services/post_alerter.rb b/app/services/post_alerter.rb
index 8c31d579ce..c4c930b5ca 100644
--- a/app/services/post_alerter.rb
+++ b/app/services/post_alerter.rb
@@ -126,6 +126,7 @@ class PostAlerter
 
       if mentioned_users
         mentioned_users = only_allowed_users(mentioned_users, post)
+        mentioned_users = mentioned_users - pm_watching_users(post)
         notified += notify_users(mentioned_users - notified, :mentioned, post, mentioned_opts)
       end
 
@@ -642,6 +643,14 @@ class PostAlerter
     users
   end
 
+  def pm_watching_users(post)
+    return [] if !post.topic.private_message?
+    directly_targeted_users(post).filter do |u|
+      notification_level = TopicUser.get(post.topic, u)&.notification_level
+      notification_level == TopicUser.notification_levels[:watching]
+    end
+  end
+
   def notify_pm_users(post, reply_to_user, quoted_users, notified)
     return [] unless post.topic
 
@@ -660,8 +669,7 @@ class PostAlerter
     users = directly_targeted_users(post).reject { |u| notified.include?(u) }
     DiscourseEvent.trigger(:before_create_notifications_for_users, users, post)
     users.each do |user|
-      notification_level = TopicUser.get(post.topic, user)&.notification_level
-      if reply_to_user == user || notification_level == TopicUser.notification_levels[:watching] || user.staged?
+      if reply_to_user == user || pm_watching_users(post).include?(user) || user.staged?
         create_notification(user, Notification.types[:private_message], post, skip_send_email_to: emails_to_skip_send)
       end
     end
diff --git a/spec/services/category_hashtag_data_source_spec.rb b/spec/services/category_hashtag_data_source_spec.rb
index 7e0a88c9f7..2084bb0ae6 100644
--- a/spec/services/category_hashtag_data_source_spec.rb
+++ b/spec/services/category_hashtag_data_source_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 RSpec.describe CategoryHashtagDataSource do
-  fab!(:parent_category) { Fabricate(:category, slug: "fun") }
+  fab!(:parent_category) { Fabricate(:category, slug: "fun", topic_count: 2) }
   fab!(:category1) do
     Fabricate(:category, slug: "random", topic_count: 12, parent_category: parent_category)
   end
@@ -71,7 +71,7 @@ RSpec.describe CategoryHashtagDataSource do
   describe "#search_without_term" do
     it "returns distinct categories ordered by topic_count" do
       expect(described_class.search_without_term(guardian, 5).map(&:slug)).to eq(
-        ["books", "movies", "casual", "random", "#{uncategorized_category.slug}"],
+        ["books", "movies", "casual", "random", "fun"],
       )
     end
 
diff --git a/spec/services/post_alerter_spec.rb b/spec/services/post_alerter_spec.rb
index 8f2b5e6830..4fb69e2a06 100644
--- a/spec/services/post_alerter_spec.rb
+++ b/spec/services/post_alerter_spec.rb
@@ -83,6 +83,17 @@ RSpec.describe PostAlerter do
 
     end
 
+    it "notifies about private message even if direct mention" do
+      pm = Fabricate(:topic, archetype: 'private_message', category_id: nil)
+      op = Fabricate(:post, topic: pm, user: pm.user, raw: "Hello @#{user.username}, nice to meet you")
+      pm.allowed_users << pm.user
+      pm.allowed_users << user
+      TopicUser.create!(user_id: user.id, topic_id: pm.id, notification_level: TopicUser.notification_levels[:watching])
+      PostAlerter.post_created(op)
+
+      expect(Notification.where(user_id: user.id).pluck_first(:notification_type)).to eq(Notification.types[:private_message])
+    end
+
     context "with group inboxes" do
       fab!(:user1) { Fabricate(:user) }
       fab!(:user2) { Fabricate(:user) }
@@ -758,15 +769,18 @@ RSpec.describe PostAlerter do
             before do
               set_topic_notification_level(alice, pm_topic, notification_level)
             end
+            let(:expected_notification) {
+              notification_level == :watching ? :private_message : :mentioned
+            }
 
             it "notifies about @username mention" do
               args = { user: bob, topic: pm_topic, raw: 'Hello @alice' }
-              expect { create_post_with_alerts(args) }.to add_notification(alice, :mentioned)
+              expect { create_post_with_alerts(args) }.to add_notification(alice, expected_notification)
             end
 
             it "notifies about @username mentions by non-human users" do
               args = { user: Discourse.system_user, topic: pm_topic, raw: 'Hello @alice' }
-              expect { create_post_with_alerts(args) }.to add_notification(alice, :mentioned)
+              expect { create_post_with_alerts(args) }.to add_notification(alice, expected_notification)
             end
 
             it "notifies about @group mention when allowed user is part of group" do