we are seeing our service getting either empty locale or locale in the format {language}{region}{variant} e.g. zh_CN_#Hans or zh_CN

The only client making call is an chrome extension and we use chrome.i18n.getUILangauge() to get the browser language and pass that as locale. When we debug we see the value of format {langauge}-{region}-{variant} e.g. zh-CN

Wondering if there are any edge cases where the chrome.i18n.getUILanguage() will every produce empty string or locale in the first format

Thanks