https://docs.mongodb.com/v4.0/reference/collation-locales-defaults/
according to above content, index creations with below locale are all failed.
{ locale: "zh@collation=pinyin" } { locale: "zh_Hant@collation=stroke" } { locale: "lk" } { locale: "li@collation=phonetic" }
can you team please confirm whether they are all typos ?
mongos> db.version()
4.0.9