[jefftk]

Thanks! I see what's happening now: news.google.com is loading AMP links in a width=100% height=100% iframe. This means your scrolling affects the iframe and not the page. Chrome, however, uses scrolling of the top level page to determine whether the address bar should hide/show. So this gives two weird things:

* If you click on an AMP link without scrolling down enough to hide the URL bar, the URL bar remains even as you scroll through the AMP article.

* If you click on an AMP link after scrolling down enough to hide the URL bar (the case you saw), the URL bar stays hidden even if you scroll back up (unless you scroll all the way to the top, at which point you're scrolling the outer page).

I agree this is bad UX, and it happens because the Google News site is loading AMP pages in an iframe. Web Packaging fixes this: https://blog.cloudflare.com/announcing-amp-real-url/

(Disclosure: I work at Google on unrelated things, speaking for myself and not the company)