Swiper Slider doesn't "snap" to slide positions

Swiper Slider scrolls like a normal horizontally scrolling container and doesn’t “snap” at slide positions.

EDIT: It seems to me that the slider starts working normally when all the images in the slides load properly. Is there any way to initialize it fully before the images in the slider load completely?

Here’s my HTML:

<div class="swiper-container slim-swiper card">
    <div class="swiper-wrapper">
        {{#each slides}}
         <a class="swiper-slide" href="{{ path }}"  style="background-image: url({{ image }});"></a>

Here’s my JS:
(after compiling the slides)

app.swiper.create('.slim-swiper', {
    speed: 300,
    spaceBetween: 100

Also, the swiper seems to be initialized correctly (the “swiper-container-initialized” class is added to the container).