1) Bootstrap Studio's built-in animation effects are disabled on mobile by default.
2) The jumpiness is probably due to the fact that you're loading external resources from YouTube. You can use the online component I've uploaded called Youtube Video Lazyload to prevent the videos from loading instantly, or if you delay the animation of the text by a second or so it should also fix it.
BSS uses the Animate on Scroll library by Michał Sajnóg (https://github.com/michalsnik/aos)
You could add this library yourself manually, rather than using BSS Animate options, and then configure it however you like (including having it stay active on mobile.) Alternatively, there are other animate libraries out there...
https://animate.style/
https://animejs.com/
And many others, which you could use.