Hi Anthony,
I'm not exactly sure how you are expecting this to look, but I think you just need to adjust your start and end values to get your desired result. I would also not suggest animating any properties on your trigger that might cause the trigger to move, for example scale, height, and y.
Also, when running React 18 in strict mode, it's critical to kill anything you create inside an effect as React is going to mount, unmount, and then mount every component. That's why you are seeing 2 sets or markers because it created 2 ScrollTriggers.
https://reactjs.org/docs/strict-mode.html#ensuring-reusable-state
So I would suggest using a wrapper as the trigger, and then if necessary, adjust the start value.
https://codesandbox.io/s/muddy-meadow-hbpqlw?file=/src/Footer.jsx