Select2 filter with multiple and allowClear plugin option can not clear all items

Prerequisites

[x] I have searched for similar issues in both open and closed tickets and cannot find a duplicate.
[x] The issue still exists against the latest master branch of yii2-grid.
[x] This is not an usage question. I confirm having gone through and read the documentation and demos.
[x] This is not a general programming / coding question. (Those should be directed to the webtips Q & A forum).
[x] I have attempted to find the simplest possible steps to reproduce the issue.
[ ] I have included a failing test as a pull request (Optional).

Steps to reproduce the issue

Trying to creat a Select2 filter with multiple and allowClear plugin options. Everything works except when 'x' is clicked to clear all items. In the console I can see the following error:

Uncaught TypeError: Cannot read property 'id' of undefined
at DecoratedClass.AllowClear._handleClear (select2.full.js?v=1579937348:1886)
at DecoratedClass._handleClear (select2.full.js?v=1579937348:598) 
...

I'm using the following code to render the widget:

<?= GridView::widget([
    'dataProvider' => $dataProvider,
    'filterModel' => $searchModel,
    'columns' => [
        //...
        [
            'attribute' => 'status',
            'format' => 'raw',
            'value' => function ($model) {
                /* @var $model Ticket */
                return $model->statusAsHtml;
            },

            'filter' => Ticket::ticketStatuses(),
            'filterType' => GridView::FILTER_SELECT2,
            'filterWidgetOptions' => [
                'pluginOptions' => [
                    'allowClear' => true,
                    'multiple' => true,
                    //'placeholder' => '',
                ],
            ],
        ],
        //...
    ],
]); ?>

If the placeholder plugin option is added the 'x' is working and there is no error in console window.

Environment

Browsers

[x] Google Chrome

Operating System

[x] Windows

Libraries

jQuery version: 2.2.4
yii2-grid version: v3.3.4

Isolating the problem

[ ] This bug happens on the demos page in the demo there is placeholder so i can not test it there
[ ] The bug happens consistently across all tested browsers
[ ] This bug happens when using yii2-grid without other plugins.

kartik-v / yii2-grid

Select2 filter with multiple and allowClear plugin option can not clear all items #951