Hello Ben

Thank you for reaching out to us.

Bootstrap v4 requires popper.js since it contains the dropdown.js library which is dependent on it. You need to make some changes to the theme. In file the functions.php file (usually in wp-content/themes/xamin/functions.php) you'll see something like this:

wp_enqueue_script( 'bootstrap', get_template_directory_uri() . '/assets/js/bootstrap.min.js', array('jquery'), '3.3.5', true );

Above that line add this:

wp_enqueue_script( 'bootstrap-poper', 'https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.0.4/popper.js', array(), null, true );

This will be overwritten when the theme is updated, so maybe a better solution would be to add the following hook to the functions.php file of your theme or the child theme:

function bootstrap_dequeue_script() {
   $pageID = get_the_ID();
   // here will be replaced id of the page where is our table
    // Can be found when you edit that page in URL for post parametar
    // Example if id is 1 (..post.php?post=1&action=edit..)
   if ($pageID == 1){
       wp_dequeue_script('bootstrap');
       wp_enqueue_script( 'bootstrap-popper', 'https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.0.4/popper.js', array('jquery'), null, true );
       wp_enqueue_script( 'bootstrap', get_template_directory_uri() . '/assets/js/bootstrap.min.js', array('jquery','bootstrap-popper'), '3.3.5', true );
   }
}
add_action( 'wp_print_scripts', 'bootstrap_dequeue_script', 100 );

You need to make sure the bootstrap file is located in the correct path, so double-check "assets/js/bootstrap.min.js".

Then, when you access the table and go to the Customize/Custom CSS field, add this:

// For example we insert id of the table 1, but you need to replace it with your table id
.wpDataTablesFilter[data-wpdatatable_id="1"] .dropdown-toggle::after {
    display:none !important;
}
.wpDataTableID-1 .dataTables_length .length_menu.show{
    display:inline-block !important;
}

It should be working fine after that.

If you have issues with this, please provide us with a temporary wp-admin user (Administrator), along with FTP access credentials, so we can do it for you.

Please note that this is a public ticket, so make sure to enable the PRIVATE response if you're sending us credentials.

Thanks for getting back to me on this, Ben.

Our developers are going to work with newer versions of Bootstrap, hopefully soon. I don't have an ETA on it yet, but they said we're already behind schedule on it due to some priority issues they had to work with.