diff --git a/awx/api/serializers.py b/awx/api/serializers.py
index f9d21b0c7d..236549a2fa 100644
--- a/awx/api/serializers.py
+++ b/awx/api/serializers.py
@@ -4442,14 +4442,15 @@ class WorkflowJobLaunchSerializer(BaseSerializer):
         return False
 
     def get_defaults(self, obj):
-        defaults ={
-            'inventory': {
-                'name': getattrd(obj, 'inventory.name', None),
-                'id': getattrd(obj, 'inventory.pk', None)
-            }
-        }
-
-        return defaults
+        defaults_dict = {}
+        for field_name in WorkflowJobTemplate.get_ask_mapping().keys():
+            if field_name == 'inventory':
+                defaults_dict[field_name] = dict(
+                    name=getattrd(obj, '%s.name' % field_name, None),
+                    id=getattrd(obj, '%s.pk' % field_name, None))
+            else:
+                defaults_dict[field_name] = getattr(obj, field_name)
+        return defaults_dict
 
     def get_workflow_job_template_data(self, obj):
         return dict(name=obj.name, id=obj.id, description=obj.description)
diff --git a/awx/api/views/__init__.py b/awx/api/views/__init__.py
index cbc879097e..87140b02b1 100644
--- a/awx/api/views/__init__.py
+++ b/awx/api/views/__init__.py
@@ -3108,6 +3108,8 @@ class WorkflowJobTemplateLaunch(WorkflowsEnforcementMixin, RetrieveAPIView):
                 data['extra_vars'] = extra_vars
             if obj.ask_inventory_on_launch:
                 data['inventory'] = obj.inventory_id
+            else:
+                data.pop('inventory', None)
         return data
 
     def post(self, request, *args, **kwargs):
diff --git a/awx/main/models/workflow.py b/awx/main/models/workflow.py
index 0f988afb79..4d6cad4b4e 100644
--- a/awx/main/models/workflow.py
+++ b/awx/main/models/workflow.py
@@ -440,6 +440,7 @@ class WorkflowJobTemplate(UnifiedJobTemplate, WorkflowJobOptions, SurveyJobTempl
                 if rejected_vars:
                     rejected_data['extra_vars'] = rejected_vars
                 errors_dict.update(vars_errors)
+                continue
 
             if field_name not in kwargs:
                 continue