Customize Checkout Html Templates

Im customizing the checkout of Magento and having some issue in html templates. I copy the cart-items.html from the magento-checkout module in my theme but, when i change the template structure the js stop running and no one error in the console.

<div class="block items-in-cart" data-bind="mageInit: {'collapsible':{'openedState': 'active', 'active': isItemsBlockExpanded()}}">
<div class="title" data-role="title">
    <strong role="heading" aria-level="1">
        <translate args="maxCartItemsToDisplay" if="maxCartItemsToDisplay < getCartLineItemsCount()"/>
        <translate args="'of'" if="maxCartItemsToDisplay < getCartLineItemsCount()"/>
        <span data-bind="text: getCartSummaryItemsCount()"></span>
        <translate args="'Item in Cart'" if="getCartLineItemsCount() === 1"/>
        <translate args="'Items in Cart'" if="getCartLineItemsCount() > 1"/>
    </strong>
</div>

Im my template i changed for this

<div class="block items-in-cart">
<div class="title" data-role="title">
        <span data-bind="text: getCartSummaryItemsCount()"></span> Item (s)
</div>

but the

data-bind="text: getCartSummaryItemsCount()"
not working. Can someone explain to me please?