Issue with Post field type and "select_advanced"

Hi there,

We've recently updated Metabox and our extension, unfortunaltey i can't tell which version we had previously installed. Since this update to todays latest version of Metabox and all the extension we're using, we are facing the following issue which wasn't one for more than 1,5 years.

We have "post" fields to choose posts/pages rom any post types and as field_type we are using "selected_advanced". This ends in https://example.com/wp-admin/admin-ajax.php 400 (Bad Request). If i change to field_type "select" all is working correctly.

Here's a code snippet, hope this helps:

'fields'          => [
                [
                    'id'          => 'login_page_id',
                    'name'        => _x( 'Login page', 'admin', 'demo' ),
                    'desc'        => _x( 'Choose your default login page. This will change the login page URL of WordPress to point to the chosen page.', 'admin', 'demo' ),
                    'type'        => 'post',
                    'post_type'   => 'any',
                    'field_type'  => 'select_advanced',
                    'placeholder' => _x( 'Default WordPress login page', 'admin', 'demo' )
                ],

Please advise, the "select" option is hard to use in environments with hundreds of posts/pages.

Best, John