My published site looks different on different computers at different times

I have a couple of issues with my published site and would appreciate it if I could get some help. I will try and explain as detailed as I can, if anything doesn’t make sense I would gladly elaborate.

  1. A blur effect visible on my design page does not show up on the published site.

  2. The published site on mobile landscape looks completely different (everything is squashed some sections are cut in half and others missing) from my design page even after using the same dimensions on my design page.

  3. The background video is set to auto-play play but it plays sometimes and other times it doesn’t.

  4. On some screens not only does the website look distraught (as in everything is placed differently from their design alignment) but their’s huge white blank boxes on top of the content that’s supposed to be there.

Link: Webflow - Neophyte site project

Here is my site Read-Only: LINK
(how to share your site Read-Only link)