Header with video background flashes On Reload or Page Change - easy fix?

Hello Everyone! This is my first post. I am new to blocs, already super excited and I built my first test site. Deployed on my linux server, and already took the header / drop down menu, made an include of it and dropped it across all my php pages so its one bit of code for the whole site.

I noticed a distinctive flash / blink as the page reloads. I wondered if something could be adding to this. My test server is behind a firewall so I cant post a link, but I am using lots of brics and maybe there is a known issue out there? I am using waves, particles, stuff like that. The header does have a video background, but its lightweight, very fast loading. The flash is noticeable because the background is white under it. maybe first step should be to change that :wink:

Disable the preloader maybe.

thank you! I will try that.