There's a discussion at the following link about how to solve this issue: https://github.com/metafizzy/flickity/issues/691

The solution is to configure the imagesLoaded property and it is documented at: https://flickity.metafizzy.co/options.html#imagesloaded

Here's example usage:

<div data-flickity='{"imagesLoaded": true}' class="carousel">
    <div class="carousel-cell">
        <img src="..."/>
    </div>
</div>