ES error on indexing flow

This in wrong SQL

    public function index_flow($id, $start_id = 0, $altmetrics=True, $verbosity=0) {

        $params['index'] = 'openml';
        $params['type'] = 'flow';

        $flows = $this->db->query('select i.*, count(rid) as runs from implementation i left join algorithm_setup s on (s.implementation_id=i.id) left join run r on (r.setup=s.sid)' . ($id ? ' where i.id=' . $id : '') . ' group by i.id');


        if ($id and ! $flows)
            return 'Error: flow ' . $id . ' is unknown';
        elseif (! $flows)
            return 'Nothing to index';
        foreach ($flows as $d) {
            $params['body'][] = array(
                'index' => array(
                    '_id' => $d->id
                )
            );

            $params['body'][] = $this->build_flow($d);
        }

        $responses = $this->client->bulk($params);

        if($responses['errors'] == True){
    foreach ($responses['items'] as $res){
    if(array_key_exists('error',$res['index'])){
      $err = $res['index']['error'];
      return 'ERROR for ID ' . $res['index']['_id'] . ' : Type:' . $err['type'] . ' Reason: ' . $err['reason'] . (array_key_exists('caused_by', $err) ? ' Caused by: ' . $err['caused_by']['reason'] : '');
      }
    }
  }

As it results in the following error:

Error Number: 1055
	Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'openml_expdb.i.fullName' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
	select i.*, count(rid) as runs from implementation i left join algorithm_setup s on (s.implementation_id=i.id) left join run r on (r.setup=s.sid) group by i.id
	Filename: core/MY_Database_Read_Model.php
	Line Number: 31

I am still trying to figure out why this error has not manifested itself before.

Start with the index_flow function and the SQL query shown in the issue, then inspect core/MY_Database_Read_Model.php at line 31 to understand where it fails. Reproduce indexing with only_full_group_by enabled and confirm the corrected query completes without the reported error and still returns the expected flow data.