Can't check checkbox - materialize / yii2 / macgyer

I use this:

<?= $form->field($model_prop, 'is_in_sleeves')->checkbox() ?>

Of course using macgyer\yii2materializecss\widgets\form\ActiveForm.

But my checkbox won't check. I get this HTML:

I looked for an answer and found only a lot of discussion about $enclosedByLabel, but it looks that Macgyer "corrected" this mistake and set $enclosedByLabel to false automatically, so there's no need to do it manually. But I still can't check my checkbox.