Site not loading properly in Edge, Brave and incognito modes

Could you take a look for me? I took all the usual steps, like turning off plugins, revision roll back, caching stuff. Switching to WP default theme does seem to work, but of course I don't want to do that.

Homepage won't finish loading in Edge, Brave, and incognito modes. Usually it won't get past white window with nav links. Example: it'll load in Chrome desktop normal window, but switch to incognito, and it won't load past blanc.

The site is very basic. I used a theme from GP sitebuilder and nothing else, but still no luck in fixing it.

We use cloud hosting.