weird background behavior on mobile?

So... for your questions:

Q:  Weird background behavior on mobile?
A:  I use desktop and the mobile view settings. I don't actually see anything weird happening with your background so I don't know.

Q:  My background image seems to be bulging?
A:  Nope, not from what I see.

Q:  I recently added a loading screen and a snowflake animation but idk why either of those would cause this???
A:  I don't actually see them affect your background. I do see them affecting your view port because my screen does scroll up on its own if I go down to the very bottom of your page and the "snowflake" reaches the bottom in mobile view.

Q:  I have a shaking animation in my layout that cause certain things like floaties to act weirdly, so maybe thats part of this?
A:  Nope. Hover affects on images, wouldn't affect the background.

I think your "snowflake animation" is the issue.
If you have any margin or top settings that are negative, or over 100%, or just a very large number, that would place it outside of the view port (device view) would create this scrolling behavior.

Just try to adjust those settings or use overflow:hidden just be careful using overflow:hidden it could make your page unscrollable.

Hope this helps ^_^