Site logo not loading on mobile

I have created a site using customify and all is working well, except for an issue with the site logo.

On a desktop browser the logo renders as it should.
In the customise preview for the mobile view the logo is shown, yet when checking from my phone the logo is replaced with a broken image symbol and the site title. If I try to open the missing logo image in a new tab I get a 404 not found message.

The logo is a 250x250px jpeg as per the recommendation.

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