Mobile-only menu flashes up briefly

Hi all,

Wondering if anyone can help me, I am using Divi's Theme Builder so I can have more personalisation with my menu headers as they are for a shop page.

In the template, I technically have three headers. The top two are for desktop only (main menu, with a secondary shop-focused menu), with the bottom header being a combination of these optimised for mobile. I have set these to be visible/invisible on desktop/tablet/mobile as necessary.

My issue is that when I load the site on either desktop or mobile, the mobile header will briefly appear before disappearing (desktop) or shrinking to size (mobile).

Is there anything I can do about this? Thanks in advance.

Here's the shop page in question: https://simoncookeinteriors.co.uk/shop/

 

Hi there, thanks for getting back to me! I actually downloaded a preloader plugin as suggested elsewhere (so far so good!|) and I will be looking to speed up my site too. I will also have a look into that Static CSS File option - thank you for the suggestion!