Screen Time blocks Google websites because YouTube is restricted I'm using Screen Time's feature to block a website:
System Preferences -&gt; Screen Time -&gt; Content &amp; Privacy -&gt; Limit Adult Websites -&gt; Customise... -&gt; Restricted -&gt; https://youtube.com/

Funny thing is, when I try to visit google.com or any of its subdomains (drive.google.com, calendar.google.com), I get this:

I looked at the Network tab, but there I only see requests to the google.com domain, but no requests to youtube.com. And what's even funnier is that when I visit youtube.com by entering it in the address bar of the browser, it loads without any problems. Do you have any idea why Screen Time behaves like this and how to fix it?
Your problem is that Google, as part of its single sign-on (SSO) process, also logs you into YouTube. For most of the Google applications, it can set cookies that are valid on *.google.com, but for YouTube, it redirects you to https://accounts.youtube.com/accounts/SetSID with a sign-on token; you can see this URL briefly flash up when you log in.
It's this redirect that's tripping up your filter. As described in other answers, you can restrict your filter to www.youtube.com, or you might be able to explicitly whitelist accounts.youtube.com.