Steps to reproduce
- Request https://zh.wikipedia.org/api/rest_v1/page/mobile-html/贝拉克·奥巴马 with Accept-Language: zh-hant, and you'll see the article content in Traditional Chinese.
- Do the request again but with Accept-Language: zh-hans, and it still shows the article content in Traditional Chinese. (but it should be in Simplified Chinese).
Looks like the endpoint only applies the Accept-Language for the first time.