Luan,
Thanks for including a link.
The logo does not disappear for me! Unless you mean when the page reloads?
If I visit the home page, then click the button Showreel, there is a brief moment while the page refreshes that the logo does go away until the page is done rendering. This is normal behavior.
Now your site does appear to use a theme that has a transition effect applied to page loads. IMO it looks cool, but it may be accentuate the loading effect for you. There is a JavaScript that runs on your page and it effects this div:
<div id="layout" style="opacity: 1;">
This is the main page container on your site and it affects everything except the <body> background.
Its possible that you could remove your logo from this div, put it above the div, and then position it back with CSS. Since your template is responsive that is going to take a lot of work to do it right.
The JavaScript that affects this layout div is https://luanhallvfx.com/wp-content/themes/Attitude/assets/js/jquery.theme.js
You could comment out that piece of the script:
th('#layout').animate({ opacity: 1 }, 500);
But it is a cool effect. BTW the site, and your work, look awesome.