Within "CB Groupjive - Stream Notification Edit" under Action in the Code parameter you'll see the following.
Code:
. moscomprofilerHTML::radioListButtons( $listEnable, 'params[activity_new]', null, 'value', 'text', $input->get( 'post/params.activity_new', $variables['var2']->params()->get( 'activity_new', 0, \CBLib\Registry\GetterInterface::INT ), \CBLib\Registry\GetterInterface::INT ), 1, null, null, false )
Where it's getting the parameter value for the notification activity_new it has a default of 0 next to it. Change that to a 1.