The examples you show are much more complex and your version has multiple ScrollTriggers and multiple timelines which for sure makes it hard to debug or even figure out what is going on.
Mine just has one ScrollTrigger and one timeline, simple, concise and works. Why do you want to make it so complicated?
https://codepen.io/mvaneijgen/pen/ExEBKVx?editors=0010
Also what is the reason you're using Smooth Scrollbar.js and SplitType.js, these are both libraries not from GSAP, so have no guarantee to play nice with GSAP. You are free to use them off course, but it is a bit weird to ask for help on a forum that has nothing to do with these plugins. Also GSAP has perfectly capable plugins that seem to tackle the same use case, but DO play nicely with the all the other GSAP plugins, so to me it seems like a no brainer to use these instead, but of course don't feel forced to use them.
https://greensock.com/docs/v3/Plugins/ScrollSmoother
https://greensock.com/docs/v3/Plugins/SplitText