Hmmm.... Strange.... I have tried this on Chromium-based browsers on Ubuntu, MacOS and Windows.... Will check out Mint. If its a problem that I can fix, I'll implement it soon :)

So, on a base level, what happens when you go to the website is, it loads all the binaries that can be run in a sandbox inside the browser itself. So, until the site is open, your browser will have all the files needed to run the website. This downloading happens when the Loading screen appears. I'll see if I am able to reproduce this.