@Cassie
Cassie, I'd like to extend my gratitude to you and Jack. After creating a demo which I was really reluctant to do it became obvious that the problem was on my end (after seeing my demo work with no issues).
My problem was I was running the ScrollSmoother.create constructor in a main.js file:
function smoov() {
const smoother = ScrollSmoother.create({
wrapper: '#smooth-wrapper',
content: '#smooth-content',
smooth: 2,
effects: true,
});
return smoother;
}
smoov();
whilst my scrolltrigger for the pinning was in a different .js file. The separate js did not have scrollsmoother imported so that was my issue. I just assumed if it was in the main.js it would be fine but that was not the case (and since the scrolling of the actual page still had the smoothing it seemed like it was global). No console errors were thrown, although I did not check the console warnings so that may have saved me some headaches.
I also did not notice that OP was using the scrollTo and not the smoothscroll plugin so this is probably not even the right thread! My Apologies. Noobie learning a lot today!