diff --git a/nova/compute/api.py b/nova/compute/api.py
index 43a0f66a10..8170fd8f24 100644
--- a/nova/compute/api.py
+++ b/nova/compute/api.py
@@ -2857,9 +2857,11 @@ class API:
                 # spec has been archived is being queried.
                 raise exception.InstanceNotFound(instance_id=uuid)
         else:
+            if isinstance(result[cell_uuid], exception.NovaException):
+                LOG.exception(result[cell_uuid])
             raise exception.NovaException(
-                _("Cell %s is not responding and hence instance "
-                  "info is not available.") % cell_uuid)
+                _("Cell %s is not responding or returned an exception, "
+                  "hence instance info is not available.") % cell_uuid)
 
     def _get_instance(self, context, instance_uuid, expected_attrs,
                       cell_down_support=False):
diff --git a/nova/context.py b/nova/context.py
index 619c39e212..dc42b38b5b 100644
--- a/nova/context.py
+++ b/nova/context.py
@@ -424,7 +424,7 @@ def scatter_gather_cells(context, cell_mappings, timeout, fn, *args, **kwargs):
             # Only log the exception traceback for non-nova exceptions.
             if not isinstance(e, exception.NovaException):
                 LOG.exception('Error gathering result from cell %s', cell_uuid)
-            result = e.__class__(e.args)
+            result = e
         # The queue is already synchronized.
         queue.put((cell_uuid, result))
 
diff --git a/nova/tests/unit/compute/test_api.py b/nova/tests/unit/compute/test_api.py
index 4297fcff66..5a3f5d01b4 100644
--- a/nova/tests/unit/compute/test_api.py
+++ b/nova/tests/unit/compute/test_api.py
@@ -6371,8 +6371,9 @@ class _ComputeAPIUnitTestMixIn(object):
         self.assertEqual(uuids.inst, result.uuid)
         mock_get_inst.assert_called_once()
 
+    @mock.patch('nova.compute.api.LOG.exception')
     @mock.patch.object(objects.Instance, 'get_by_uuid')
-    def test_get_instance_from_cell_failure(self, mock_get_inst):
+    def test_get_instance_from_cell_failure(self, mock_get_inst, mock_log_exp):
         # Make sure InstanceNotFound is bubbled up and not treated like
         # other errors
         mock_get_inst.side_effect = exception.InstanceNotFound(
@@ -6385,6 +6386,15 @@ class _ComputeAPIUnitTestMixIn(object):
             self.compute_api._get_instance_from_cell, self.context,
             im, [], False)
         self.assertIn('could not be found', str(exp))
+        # Make sure other unexpected NovaException are logged for debugging
+        mock_get_inst.side_effect = exception.NovaException()
+        exp = self.assertRaises(
+            exception.NovaException, self.compute_api._get_instance_from_cell,
+            self.context, im, [], False)
+        msg = (f'Cell {cell_mapping.uuid} is not responding or returned an '
+            'exception, hence instance info is not available.')
+        self.assertIn(msg, str(exp))
+        mock_log_exp.assert_called_once_with(mock_get_inst.side_effect)
 
     @mock.patch('nova.compute.api.API._save_user_id_in_instance_mapping')
     @mock.patch.object(objects.RequestSpec, 'get_by_instance_uuid')