While debugging a website I saw that a part of the HTML-pages are not showing up in the Network-traffic Tab of the Developer tools (in my case Chrome browser). When I click on a link on aaaa.html, e.g. it shows me the new bbbb.html and the URL changes from aaaa.html to bbbb.html. But in the developer tools there is no request. If I do a hard refresh on this bbbb.html (click in the URL-bar and hit enter) the page of course reloads again. But this time the network traffic is showing up. Why is this like that?