diff --git a/awx/main/scheduler/__init__.py b/awx/main/scheduler/__init__.py
index 5c713e6196..670012dc57 100644
--- a/awx/main/scheduler/__init__.py
+++ b/awx/main/scheduler/__init__.py
@@ -6,7 +6,6 @@ from datetime import datetime, timedelta
 import logging
 import uuid
 from sets import Set
-import itertools
 
 # Django
 from django.conf import settings
@@ -437,7 +436,7 @@ class TaskManager():
                 if isolated:
                     # TODO: cancel and reap artifacts of lost jobs from heartbeat
                     task.job_explanation += ' '.join((
-                        'Task was marked as running in Tower but its'
+                        'Task was marked as running in Tower but its ',
                         'controller management daemon was not present in',
                         'Celery, so it has been marked as failed.',
                         'Task may still be running, but contactability is unknown.'
@@ -452,7 +451,7 @@ class TaskManager():
                 except DatabaseError:
                     logger.error("Task {} DB error in marking failed. Job possibly deleted.".format(task.log_format))
                     continue
-                awx_tasks._send_notification_templates(task, new_status)
+                awx_tasks._send_notification_templates(task, 'failed')
                 task.websocket_emit_status(new_status)
                 logger.error("{}Task {} has no record in celery. Marking as failed".format(
                     'Isolated ' if isolated else '', task.log_format))
@@ -506,16 +505,11 @@ class TaskManager():
                     active_tasks = []
                 elif instance.capacity == 0:
                     active_tasks = []
+                elif instance.rampart_groups.filter(controller__isnull=False).exists():
+                    active_tasks = all_celery_task_ids
+                    isolated = True
                 else:
-                    cids = instance.rampart_groups.filter(
-                        controller__isnull=False).values_list('id', flat=True)
-                    if cids:
-                        control_hosts = Instance.objects.filter(
-                            rampart_groups__in=cids).values_list('hostname', flat=True)
-                        active_tasks = set(itertools.chain(active_queues[host] for host in control_hosts))
-                        isolated = True
-                    else:
-                        continue
+                    continue
 
             self.fail_jobs_if_not_in_celery(
                 node_jobs, active_tasks, celery_task_start_time,
diff --git a/awx/main/tests/unit/test_task_manager.py b/awx/main/tests/unit/test_task_manager.py
index 24536adae5..1937b7b5ca 100644
--- a/awx/main/tests/unit/test_task_manager.py
+++ b/awx/main/tests/unit/test_task_manager.py
@@ -21,7 +21,7 @@ class TestCleanupInconsistentCeleryTasks():
     @mock.patch.object(TaskManager, 'get_active_tasks', return_value=([], {}))
     @mock.patch.object(TaskManager, 'get_running_tasks', return_value=({'host1': [Job(id=2), Job(id=3),]}, []))
     @mock.patch.object(InstanceGroup.objects, 'prefetch_related', return_value=[])
-    @mock.patch.object(Instance.objects, 'prefetch_related', return_value=[])
+    @mock.patch.object(Instance.objects, 'filter', return_value=mock.MagicMock(first=lambda: None))
     @mock.patch('awx.main.scheduler.logger')
     def test_instance_does_not_exist(self, logger_mock, *args):
         logger_mock.error = mock.MagicMock(side_effect=RuntimeError("mocked"))