There is a bug in “Pages in Category” subheading display in all zh wikiprojects when language converter is on, which makes the word “Category” (“分类” in Simplified Chinese or “分類” in Traditional Chinese) shows twice in the subheading.
In Simplified Chinese variant (zh-hans, zh-cn, zh-my, zh-sg), the subheading will be shown as “分类“分类:XX”中的页面” (which is wrong), instead of “分类“XX”中的页面” (which is correct).
(Example: https://zh.wikipedia.org/zh-hans/Category:2016%E5%B9%B4%E7%94%B0%E5%BE%91)
In Traditional Chinese variant (zh-hant, zh-hk, zh-mo, zh-tw), the subheading will be shown as “「分類:XX」分類的頁面” (which is wrong), instead of “「XX」分類的頁面” (which is correct).
(Example: https://zh.wikipedia.org/zh-hant/Category:2016%E5%B9%B4%E7%94%B0%E5%BE%91)
This bug does not appear in zh variant (without conversion), as the display of the Category subheading is normal as usual when zh variant is selected.