Looks like the main issue is that you don’t have any HTML/CSS up front. Make sure SSR/SSG works.
This is what you see when you load with JS disabled:
You can confirm with just running curl on that command - there’s no markup, only JS.
So to display anything on the screen requires JS hydration first.
Look into your codebase to see what could be causing this - there’s likely something near the top that is opting out of rendering.