Created attachment 382103 [details] A screenshot of the bug shown. On some pages on Wikipedia, the CSS seems to not load at all. Example: https://en.wikipedia.org/wiki/Halloween I received this report on behalf of another user, I have not experienced this issue myself. I'm on Windows 10.
Please see https://phabricator.wikimedia.org/T236743.
Can you please try on https://en.wikipedia.org/wiki/Halloween?debug=true and check the Developer Tools (network and console tabs) for errors? See https://developer.apple.com/safari/tools/
Closing due to age and lack of ability to reproduce.