It loads fine for me, but in general there are a few differences between pages.dev and Custom Domains which can cause issues:
Auto-Minify Html can break frameworks like Nuxt.js, disable under Speed -> Optimization -> Content Optimizations -> Auto Minify. Rocket Loader can cause issues as well (and isn't going to help most modern websites), you can disable there as well.
If you are forcing cache with a Page Rule or Cache Rule, it can also break things
Pages already has cache under the hood, it's just the default cache settings that sometimes get in the way. If you were using a framework that auto-generated js/css files using file hashes in the name no issue, but since you're using static file names for your css/js, they get cached and keep the old version on updates
That looks better, no new caching now at least. If you purge browser cache now, do another update, do you still get stuck in the same issue? (Old browser cache would still stick around even after you apply that, it's not a magical retroactive change, Maybe do an update to remove the anti-dev tools blocking so you can actually see whats erroring in console lol)
wonder if it's because you have Under Attack Mode enabled (btw why? You get unlimited static requests), and you hit f5 to resend the POST Request which actually hits your origin/pages this time