In the above URL one should not see any ZWSP boxes on one's screen. libwebkit2gtk-4.0-37: Installed: 2.17.5-2
Do you see lots of them on https://en.wikipedia.org/wiki/Special:RecentChanges ?
See also: https://bugs.webkit.org/show_bug.cgi?id=175778
https://en.wiktionary.org/wiki/康