Pixel Astronauts

Hey, I'm struggling to get this scrollTrigger function to work in a Vue application: import Vue from "vue"; import { gsap } from "gsap"; import ScrollTrigger from "gsap/ScrollTrigger"; const app = new Vue({ el: "#app", mounted() { ScrollTrigger.batch(".reveal", { onEnter: batch => { gsap.fromTo( batch, { y: 100 }, { autoAlpha: 1, y: 0, ease: "power4", duration: 2, stagger: 0.2 } ); }, start: "20px bottom" }); } }); When the page loads at the top of the viewport, everything works fine. But if I refresh on another point on the page I'm getting the following error: Cannot read property 'pin' of undefined Why is this happening and what can I do about it?