Ah ok, I've got a few sites dealing with the images in a similar way, and they all seem work fine up to a point, usually around their intrinsic width and past that point that's where the scroll offset calculations seems to go a bit crazy, you're right in that the demo seems to be behaving now, where's the best place to grab the latest versions as the sites in question are using NPM and Laravel Mix?
Really appreciate the speedy fix though!