diff --git a/app/models/namespaces/traversal/linear.rb b/app/models/namespaces/traversal/linear.rb
index 394e01843fdd86d7d652c9fe5940060f66a65d75..19daac030ac1259045ca9bcf80e6807c96627f74 100644
--- a/app/models/namespaces/traversal/linear.rb
+++ b/app/models/namespaces/traversal/linear.rb
@@ -233,7 +233,8 @@ def set_traversal_ids
         return if is_a?(Namespaces::ProjectNamespace)
 
         self.transient_traversal_ids = if parent_id
-                                         parent.traversal_ids + [id]
+                                         # remove safe navigation and `.to_a` with https://gitlab.com/gitlab-org/gitlab/-/issues/508611
+                                         parent&.traversal_ids.to_a + [id]
                                        else
                                          [id]
                                        end
diff --git a/app/services/groups/destroy_service.rb b/app/services/groups/destroy_service.rb
index e868d2a2fa97fb1141705af64ed33eb4f5825895..dc6f49eb0009539f1a5a709f8232a9a677cd2a74 100644
--- a/app/services/groups/destroy_service.rb
+++ b/app/services/groups/destroy_service.rb
@@ -118,7 +118,7 @@ def publish_event
       event = Groups::GroupDeletedEvent.new(
         data: {
           group_id: group.id,
-          root_namespace_id: group.root_ancestor.id
+          root_namespace_id: group.root_ancestor&.id.to_i # remove safe navigation and `.to_i` with https://gitlab.com/gitlab-org/gitlab/-/issues/508611
         }
       )
 
diff --git a/db/docs/batched_background_migrations/delete_orphaned_groups.yml b/db/docs/batched_background_migrations/delete_orphaned_groups.yml
index c8d84dc1c66b7b5fdca38b7eeb6184eac5480522..b91d5698f15b7a18cc7a48a4e3d3d4fddf525567 100644
--- a/db/docs/batched_background_migrations/delete_orphaned_groups.yml
+++ b/db/docs/batched_background_migrations/delete_orphaned_groups.yml
@@ -4,5 +4,5 @@ description: Deletes orhpaned groups whose parent's does not exist
 feature_category: groups_and_projects
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/172420
 milestone: '17.7'
-queued_migration_version: 20241112163029
+queued_migration_version: 20241206154945
 finalized_by: # version of the migration that finalized this BBM
diff --git a/db/post_migrate/20241112163029_queue_delete_orphaned_groups.rb b/db/post_migrate/20241112163029_queue_delete_orphaned_groups.rb
index 4e2d7d702b40ecc9a9fa9662d21de8b5a37ea5c6..1f42797685a5ea7030b41e78a6c3abf4ba1718d6 100644
--- a/db/post_migrate/20241112163029_queue_delete_orphaned_groups.rb
+++ b/db/post_migrate/20241112163029_queue_delete_orphaned_groups.rb
@@ -10,19 +10,12 @@ class QueueDeleteOrphanedGroups < Gitlab::Database::Migration[2.2]
   SUB_BATCH_SIZE = 100
 
   def up
-    return unless Gitlab.com_except_jh? && !Gitlab.staging?
-
-    queue_batched_background_migration(
-      MIGRATION,
-      :namespaces,
-      :id,
-      job_interval: DELAY_INTERVAL,
-      batch_size: BATCH_SIZE,
-      sub_batch_size: SUB_BATCH_SIZE
-    )
+    # no-op because there was a bug in the original migration, which has been
+    # fixed by https://gitlab.com/gitlab-org/gitlab/-/merge_requests/174995
   end
 
   def down
-    delete_batched_background_migration(MIGRATION, :namespaces, :id, [])
+    # no-op because there was a bug in the original migration, which has been
+    # fixed in https://gitlab.com/gitlab-org/gitlab/-/merge_requests/174995
   end
 end
diff --git a/db/post_migrate/20241206154945_queue_requeue_delete_orphaned_groups.rb b/db/post_migrate/20241206154945_queue_requeue_delete_orphaned_groups.rb
new file mode 100644
index 0000000000000000000000000000000000000000..1646b0cf7a905366f17068a6c5504a7583363ed8
--- /dev/null
+++ b/db/post_migrate/20241206154945_queue_requeue_delete_orphaned_groups.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+class QueueRequeueDeleteOrphanedGroups < Gitlab::Database::Migration[2.2]
+  milestone '17.7'
+  restrict_gitlab_migration gitlab_schema: :gitlab_main
+
+  MIGRATION = "DeleteOrphanedGroups"
+  DELAY_INTERVAL = 2.minutes
+  BATCH_SIZE = 1000
+  SUB_BATCH_SIZE = 100
+
+  def up
+    return unless Gitlab.com_except_jh? && !Gitlab.staging?
+
+    # Clear previous background migration execution from QueueDeleteOrphanedGroups
+    delete_batched_background_migration(MIGRATION, :namespaces, :id, [])
+
+    queue_batched_background_migration(
+      MIGRATION,
+      :namespaces,
+      :id,
+      job_interval: DELAY_INTERVAL,
+      batch_size: BATCH_SIZE,
+      sub_batch_size: SUB_BATCH_SIZE
+    )
+  end
+
+  def down
+    delete_batched_background_migration(MIGRATION, :namespaces, :id, [])
+  end
+end
diff --git a/db/schema_migrations/20241206154945 b/db/schema_migrations/20241206154945
new file mode 100644
index 0000000000000000000000000000000000000000..698f5d6872e140d42f4fa2752bf3a5aba0f524ea
--- /dev/null
+++ b/db/schema_migrations/20241206154945
@@ -0,0 +1 @@
+276b46068ee45bbafbe5c51cf466cf2cee0ec0c08d273899ccba3b5e05c93f1d
\ No newline at end of file
diff --git a/ee/app/models/concerns/elastic/maintain_elasticsearch_on_group_update.rb b/ee/app/models/concerns/elastic/maintain_elasticsearch_on_group_update.rb
index 854f938bdab8382ae38412ff8597debdfb868dfb..18015f0ccb006adbc722e2b96ba593387c24a944 100644
--- a/ee/app/models/concerns/elastic/maintain_elasticsearch_on_group_update.rb
+++ b/ee/app/models/concerns/elastic/maintain_elasticsearch_on_group_update.rb
@@ -25,7 +25,8 @@ def maintain_group_associations_on_update
 
     def maintain_group_associations_on_destroy
       delete_group_wiki_in_elastic if use_elasticsearch?
-      delete_group_associations
+      # remove if condition with https://gitlab.com/gitlab-org/gitlab/-/issues/508611
+      delete_group_associations if root_ancestor
     end
 
     def sync_group_wiki_in_elastic
diff --git a/ee/app/models/ee/group.rb b/ee/app/models/ee/group.rb
index cb2590e3495da73cd77e0c83c5f86975b1a89d15..da2bc6783b5732f77a82439dcbf0b404079351dd 100644
--- a/ee/app/models/ee/group.rb
+++ b/ee/app/models/ee/group.rb
@@ -1155,7 +1155,7 @@ def execute_subgroup_hooks(event)
         # When this subgroup is removed, there is no point in this subgroup's webhook itself being notified
         # that `self` was removed. Rather, we should only care about notifying its ancestors
         # and hence we need to trigger the hooks starting only from its `parent` group.
-        parent.execute_hooks(data, :subgroup_hooks)
+        parent&.execute_hooks(data, :subgroup_hooks) # remove safe navigation with https://gitlab.com/gitlab-org/gitlab/-/issues/508611
       end
     end
 
diff --git a/lib/gitlab/background_migration/delete_orphaned_groups.rb b/lib/gitlab/background_migration/delete_orphaned_groups.rb
index a032ad40180b684cc93867480887a760a26df342..428867ad400257d6a91f48df8eba301b6b5f0e42 100644
--- a/lib/gitlab/background_migration/delete_orphaned_groups.rb
+++ b/lib/gitlab/background_migration/delete_orphaned_groups.rb
@@ -14,7 +14,7 @@ def perform
           .joins("LEFT JOIN namespaces AS parent ON namespaces.parent_id = parent.id")
           .where(parent: { id: nil })
           .pluck(:id).each do |orphaned_group_id|
-            ::GroupDestroyWorker.perform(orphaned_group_id, admin_bot.id)
+            ::GroupDestroyWorker.perform_async(orphaned_group_id, admin_bot.id)
           end
         end
       end
diff --git a/lib/gitlab/hook_data/subgroup_builder.rb b/lib/gitlab/hook_data/subgroup_builder.rb
index a620219675a4af98221ecd5fa82f9e0981d0ccde..5ce4151f0b7da882422f94ff6265e3782b13e9c0 100644
--- a/lib/gitlab/hook_data/subgroup_builder.rb
+++ b/lib/gitlab/hook_data/subgroup_builder.rb
@@ -34,6 +34,8 @@ def event_data(event)
       def group_data
         parent = group.parent
 
+        return super unless parent
+
         super.merge(
           parent_group_id: parent.id,
           parent_name: parent.name,
diff --git a/spec/lib/gitlab/background_migration/delete_orphaned_groups_spec.rb b/spec/lib/gitlab/background_migration/delete_orphaned_groups_spec.rb
index f94d9256352a71ebf2806ab89690155cbf5c093a..717ebb1546a7b3351c0ebf0c842bed569cf4b741 100644
--- a/spec/lib/gitlab/background_migration/delete_orphaned_groups_spec.rb
+++ b/spec/lib/gitlab/background_migration/delete_orphaned_groups_spec.rb
@@ -3,10 +3,15 @@
 require 'spec_helper'
 
 RSpec.describe Gitlab::BackgroundMigration::DeleteOrphanedGroups, feature_category: :groups_and_projects do
-  let(:organization) { table(:organizations).create!(name: 'organization', path: 'organization') }
   let(:namespaces) { table(:namespaces) }
-  let!(:parent) { namespaces.create!(name: 'Group', type: 'Group', path: 'space1', organization_id: organization.id) }
-  let!(:group) { namespaces.create!(name: 'GitLab', type: 'Group', path: 'group1', organization_id: organization.id) }
+  let!(:parent) { namespaces.create!(name: 'Group', type: 'Group', path: 'space1') }
+  let!(:group) { namespaces.create!(name: 'GitLab', type: 'Group', path: 'group1') }
+  let!(:admin_bot) { ::Users::Internal.admin_bot }
+  let!(:orphaned_groups) do
+    (1..4).map do |i|
+      namespaces.create!(name: "Group #{i}", path: "orphaned_group_#{i}", type: 'Group', parent_id: parent.id)
+    end
+  end
 
   subject(:background_migration) do
     described_class.new(
@@ -24,6 +29,7 @@
     before do
       # Remove constraint so we can create invalid records
       ApplicationRecord.connection.execute("ALTER TABLE namespaces DROP CONSTRAINT fk_7f813d8c90;")
+      (1..4).map { |i| namespaces.create!(name: "Group #{i}", path: "group_#{i}", type: 'Group', parent_id: group.id) }
     end
 
     after do
@@ -34,26 +40,11 @@
       SQL
     end
 
-    it 'enqueues ::GroupDestroyWorker for each group whose parent\'s do not exist' do
-      orphaned_groups = (1..4).map do |i|
-        namespaces.create!(name: "Group #{i}", path: "orphaned_group_#{i}", type: 'Group', parent_id: parent.id,
-          organization_id: organization.id)
-      end
-      groups = (1..4).map do |i|
-        namespaces.create!(name: "Group #{i}", path: "group_#{i}", type: 'Group', parent_id: group.id,
-          organization_id: organization.id)
-      end
+    it 'enqueues ::GroupDestroyWorker for each group whose parent\'s do not exist and destroys them', :sidekiq_inline do
       parent.destroy!
 
-      orphaned_groups.each do |group|
-        expect(::GroupDestroyWorker).to receive(:perform).with(group.id, ::Users::Internal.admin_bot.id)
-      end
-
-      groups.each do |group|
-        expect(::GroupDestroyWorker).not_to receive(:perform).with(group.id, ::Users::Internal.admin_bot.id)
-      end
-
-      background_migration
+      expect { background_migration }.to change { namespaces.count }.from(10).to(6)
+        .and change { namespaces.where(id: orphaned_groups.pluck(:id)).count }.from(4).to(0)
     end
   end
 end
diff --git a/spec/migrations/20241112163029_queue_delete_orphaned_groups_spec.rb b/spec/migrations/20241112163029_queue_delete_orphaned_groups_spec.rb
index d4e514b53dd2d9683d73ac793e2de02688c692de..ce37b8a865c5f9ad773c1e480f7fc113124b89d0 100644
--- a/spec/migrations/20241112163029_queue_delete_orphaned_groups_spec.rb
+++ b/spec/migrations/20241112163029_queue_delete_orphaned_groups_spec.rb
@@ -8,42 +8,8 @@
 
   it 'does not schedule a new batched migration' do
     reversible_migration do |migration|
-      migration.before -> {
-        expect(batched_migration).not_to have_scheduled_batched_migration
-      }
-
-      migration.after -> {
-        expect(batched_migration).not_to have_scheduled_batched_migration
-      }
-    end
-  end
-
-  context 'when executed on .com' do
-    before do
-      allow(Gitlab).to receive(:com_except_jh?).and_return(true)
-    end
-
-    describe '#up' do
-      it 'schedules background migration' do
-        migrate!
-
-        expect(batched_migration).to have_scheduled_batched_migration(
-          table_name: :namespaces,
-          column_name: :id,
-          interval: described_class::DELAY_INTERVAL,
-          batch_size: described_class::BATCH_SIZE,
-          sub_batch_size: described_class::SUB_BATCH_SIZE
-        )
-      end
-    end
-
-    describe '#down' do
-      it 'removes scheduled background migrations' do
-        migrate!
-        schema_migrate_down!
-
-        expect(batched_migration).not_to have_scheduled_batched_migration
-      end
+      migration.before -> { expect(batched_migration).not_to have_scheduled_batched_migration }
+      migration.after -> { expect(batched_migration).not_to have_scheduled_batched_migration }
     end
   end
 end
diff --git a/spec/migrations/20241206154945_queue_requeue_delete_orphaned_groups_spec.rb b/spec/migrations/20241206154945_queue_requeue_delete_orphaned_groups_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..47aee132a0eb5dfa2e84f50435607bf6d0a0adec
--- /dev/null
+++ b/spec/migrations/20241206154945_queue_requeue_delete_orphaned_groups_spec.rb
@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require_migration!
+
+RSpec.describe QueueRequeueDeleteOrphanedGroups, migration: :gitlab_main, feature_category: :groups_and_projects do
+  let!(:batched_migration) { described_class::MIGRATION }
+
+  it 'does not schedule a new batched migration' do
+    reversible_migration do |migration|
+      migration.before -> {
+        expect(batched_migration).not_to have_scheduled_batched_migration
+      }
+
+      migration.after -> {
+        expect(batched_migration).not_to have_scheduled_batched_migration
+      }
+    end
+  end
+
+  context 'when executed on .com' do
+    before do
+      allow(Gitlab).to receive(:com_except_jh?).and_return(true)
+    end
+
+    describe '#up' do
+      it 'schedules background migration' do
+        migrate!
+
+        expect(batched_migration).to have_scheduled_batched_migration(
+          table_name: :namespaces,
+          column_name: :id,
+          interval: described_class::DELAY_INTERVAL,
+          batch_size: described_class::BATCH_SIZE,
+          sub_batch_size: described_class::SUB_BATCH_SIZE
+        )
+      end
+    end
+
+    describe '#down' do
+      it 'removes scheduled background migrations' do
+        migrate!
+        schema_migrate_down!
+
+        expect(batched_migration).not_to have_scheduled_batched_migration
+      end
+    end
+  end
+end