diff --git a/lms/djangoapps/grades/models.py b/lms/djangoapps/grades/models.py
index eabebf861f..5ea359885e 100644
--- a/lms/djangoapps/grades/models.py
+++ b/lms/djangoapps/grades/models.py
@@ -16,7 +16,7 @@ from lazy import lazy
 import logging
 
 from django.core.exceptions import ValidationError
-from django.db import models
+from django.db import models, transaction
 from django.utils.timezone import now
 from model_utils.models import TimeStampedModel
 
@@ -330,16 +330,17 @@ class PersistentSubsectionGrade(TimeStampedModel):
         user_id = kwargs.pop('user_id')
         usage_key = kwargs.pop('usage_key')
         attempted = kwargs.pop('attempted')
-        grade, _ = cls.objects.update_or_create(
-            user_id=user_id,
-            course_id=usage_key.course_key,
-            usage_key=usage_key,
-            defaults=kwargs,
-        )
-        if attempted and not grade.first_attempted:
-            grade.first_attempted = now()
-        grade.full_clean()
-        grade.save()
+        with transaction.atomic():
+            grade, _ = cls.objects.update_or_create(
+                user_id=user_id,
+                course_id=usage_key.course_key,
+                usage_key=usage_key,
+                defaults=kwargs,
+            )
+            if attempted and not grade.first_attempted:
+                grade.first_attempted = now()
+                grade.save()
+            grade.full_clean()
         return grade
 
     @classmethod
diff --git a/lms/djangoapps/grades/tests/test_tasks.py b/lms/djangoapps/grades/tests/test_tasks.py
index 153ec574dc..b97a812e0a 100644
--- a/lms/djangoapps/grades/tests/test_tasks.py
+++ b/lms/djangoapps/grades/tests/test_tasks.py
@@ -113,7 +113,7 @@ class RecalculateSubsectionGradeTest(ModuleStoreTestCase):
         with self.store.default_store(default_store):
             self.set_up_course()
             self.assertTrue(PersistentGradesEnabledFlag.feature_enabled(self.course.id))
-            with check_mongo_calls(2) and self.assertNumQueries(23 + added_queries):
+            with check_mongo_calls(2) and self.assertNumQueries(24 + added_queries):
                 self._apply_recalculate_subsection_grade()
 
     @patch('lms.djangoapps.grades.signals.signals.SUBSECTION_SCORE_CHANGED.send')
@@ -161,7 +161,7 @@ class RecalculateSubsectionGradeTest(ModuleStoreTestCase):
             self.assertTrue(PersistentGradesEnabledFlag.feature_enabled(self.course.id))
             ItemFactory.create(parent=self.sequential, category='problem', display_name='problem2')
             ItemFactory.create(parent=self.sequential, category='problem', display_name='problem3')
-            with check_mongo_calls(2) and self.assertNumQueries(23 + added_queries):
+            with check_mongo_calls(2) and self.assertNumQueries(24 + added_queries):
                 self._apply_recalculate_subsection_grade()
 
     @ddt.data(ModuleStoreEnum.Type.mongo, ModuleStoreEnum.Type.split)
@@ -172,7 +172,7 @@ class RecalculateSubsectionGradeTest(ModuleStoreTestCase):
             with check_mongo_calls(2) and self.assertNumQueries(0):
                 self._apply_recalculate_subsection_grade()
 
-    #@skip("Pending completion of TNL-5089")
+    @skip("Pending completion of TNL-5089")
     @ddt.data(
         (ModuleStoreEnum.Type.mongo, True),
         (ModuleStoreEnum.Type.split, True),