WordPress site not loading correctly

Hi,

I’m currently having an issue with The Mile End website not loading correctly. After refreshing, the page will load properly, but when first opened the top logo/white header sits much larger and the homepage video is squished in.

Also when loading some pages the page will initially glitch before loading properly without having to be refreshed.

I tried to find the issue but haven’t had much luck.

Can I please have some help with fixing this?

The page I need help with: [log in to see the link]