When saving the generated access token in the oauth2_provider_accesstoken model the created and updated timestamp is null

So I have deployed my Django application which serves as a back-end to my Angular 2 web application. Now when I'm authenticating my request it is supposed to generate an access token and save it in the oauth2_provider_accesstoken model. However it throws an integrity error stating that the created and updated columns are null (which are supposed to have an auto generated timestamp). Everything works on my local setup, so not sure what is wrong.

Here is the stack trace:-

return view(request, *args, **kwargs)
 File "/home/ubuntu/.local/lib/python2.7/site-packages/django/utils/decorators.py", line 63, in bound_func
    return func.__get__(self, type(self))(*args2, **kwargs2)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/oauth2_provider/views/base.py", line 176, in post
    url, headers, body, status = self.create_token_response(request)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/oauth2_provider/views/mixins.py", line 125, in create_token_response
    return core.create_token_response(request)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/oauth2_provider/oauth2_backends.py", line 139, in create_token_response
    headers, extra_credentials)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/oauthlib/oauth2/rfc6749/endpoints/base.py", line 64, in wrapper
    return f(endpoint, uri, *args, **kwargs)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/oauthlib/oauth2/rfc6749/endpoints/token.py", line 118, in create_token_response
    request, self.default_token_type)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/oauthlib/oauth2/rfc6749/grant_types/resource_owner_password_credentials.py", line 121, in create_token_response
    self.request_validator.save_token(token, request)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/oauthlib/oauth2/rfc6749/request_validator.py", line 246, in save_token
    return self.save_bearer_token(token, request, *args, **kwargs)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/utils/decorators.py", line 185, in inner
    return func(*args, **kwargs)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/oauth2_provider/oauth2_validators.py", line 365, in save_bearer_token
    access_token = self._create_access_token(expires, request, token)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/oauth2_provider/oauth2_validators.py", line 390, in _create_access_token
    access_token.save()
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/models/base.py", line 806, in save
    force_update=force_update, update_fields=update_fields)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/models/base.py", line 836, in save_base
    updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/models/base.py", line 922, in _save_table
    result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/models/base.py", line 961, in _do_insert
    using=using, raw=raw)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/models/query.py", line 1060, in _insert
    return query.get_compiler(using=using).execute_sql(return_id)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 1099, in execute_sql
    cursor.execute(sql, params)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/backends/utils.py", line 80, in execute
    return super(CursorDebugWrapper, self).execute(sql, params)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/backends/utils.py", line 65, in execute
    return self.cursor.execute(sql, params)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/utils.py", line 94, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/home/ubuntu/.local/lib/python2.7/site-packages/django/db/backends/utils.py", line 65, in execute
    return self.cursor.execute(sql, params)
IntegrityError: null value in column "created" violates not-null constraint
DETAIL:  Failing row contains (40, FCwZR6ril2mWKiLyhy1pzSJNYsngCo, 2018-07-09 21:41:37.617994+00, read write, 1, 1, null, null).

Thanks in advance !!