SecurityAdmin-Members: GridField CSV Export - first column, no values

[MLindenhofer]

Affected Version

CMS Version: 4.10.0

Description

I've tried to customize the ExportColumns of the GridFieldExportButton of the SecurityAdmin for the Members gridfield with the setExportColumns()-method but regardless which DB-Field was on first position in the array the values for this column are empty in the exported CSV. It does not happen with the default or customized summary-fields! Seems to be a bug.

Steps to Reproduce

• Create an SecurityAdmin Extension
• fetch the Members gridfield component
• setExportColumns
• Export CSV

Example

$membersConfig = $form->Fields()->dataFieldByName('Members')->getConfig();
$btn =  $membersConfig->getComponentByType(GridFieldExportButton::class);
$btn->setExportColumns([
    'FirstName'
    'Surname',
    'Email',
    'Phone',
    'PhoneDirectDial'
]);

Screenshot: