Infinite scroll doesn't infinitely scroll

I have an infinitely scrolling section and initially, it worked but then it stopped infinitely scrolling. It ends and then restarts with blank space in between. Any ideas why?

Site: https://collie-sawfish-km3y.squarespace.com/

PW: brineintopedro

This is the code I'm using:

section[data-section-id="63fe34c80e256a7c9b9e09a2"]{
* {
  box-sizing: border-box;
}

body {
  margin: 0;
}

.marquee {
/*   overflow: hidden; */
}

.marquee-content {
  display: flex;
  animation: scrolling 10s linear infinite;
}

.marquee-item {
  flex: 0 0 16vw;
  margin: 0 0vw;
/*   flex: 0 0 20vw; */
/*   margin: 0 2vw; */
}

.marquee-item img {
  display: block;
  width: 100%;
/*   padding: 0 0px; */
}

@keyframes scrolling {
  0% { transform: translateX(0); }
  100% { transform: translatex(-144vw); }
  }
}