Fancy transform-based loading animation skipping on mobile

Hello all!

I’m designing my portfolio website, and built a cool atom loading ‘bar’ which I’m really happy with on desktop. HOWEVER on mobile, for some reason that I cannot for the life of me figure out, my animation skips for the first crucial few seconds, before become smooth again.

Here it is working smoothly on computers:
DESKTOP ATOM

And here it is glitching for a couple of seconds on mobile:
MOBILE ATOM

Any thoughts or ideas on what might be causing this?? Is it due to my site being too large asset-wise? (it’s very media-heavy)

Here is my public share link: LINK