This does not happen with any other chromium based browser
My phone locale is set to Italian with English as second language. IP address is Italian. I’m not understanding why sites like f-droid, Google dev documentation, gitlab, are all defaulting to Chinese as I can’t read it…
Sometimes I can find a link to switch back to either English or Italian, but the next visit they revert to Chinese…
Can you remove zh-Hans-cn from Firefox and just keep zh-cn?
Zh-Hans is redundant here - it is for simplified Chinese, while zh-Hant would be used for traditional chinese. But both are not well implemented and usually people only use the country codes. Zh-cn is already simplified Chinese. Zh-TW (for Taiwan) is often used to cover traditional chinese.
It’d be interesting to see if you get the same bug if zh-hans-cn is added to chrome, as it seems its the actual language tag that is causing the issue and possibly not related to the specific browser at all.