Language detector not really working

[FabricioZProx]

🐛 Bug Report

I am runing a i18next instance with language detector and i18next-fs-backend.
The language detetor does work properly. First I was using the header detector and my own detector, an although both are able to catch the locale. And the after executing the detector debug log shows:
i18next: languageChanged en
But i18n still uses the fallback option. I must manually call changeLanguage() in order to make it work properly.
After using changeLanguage() is get the same log:
i18next: languageChanged en
But this time language is working properly

To Reproduce

const i18n = require("i18next");
const i18fs = require("i18next-fs-backend");
const i18nMiddleware = require('i18next-http-middleware');
const IOTError = require('../../configuration/errors/IOTError');
const urlLookup = require("./urlLookup")

const path = require("path");

exports.i18nInit = () => {
    /*const languageDetector = new i18nMiddleware.LanguageDetector();
    languageDetector.addDetector(urlLookup);*/

    const options = {
        initImmediate: false,
        preload: ["es", "en"],
        fallbackLng: "es",
        fallbackNS: "common",
        ns: ["common"],
        debug: true,//process.env.VERBOSE_DEBUG,
        backend: {
            loadPath: path.resolve("./") + "/service/locales/{{lng}}/{{ns}}.json",
        },
        detection: {
            order: ['urlParam'],
            caches: false
        }
    };
    i18n.use(languageDetector).use(i18fs).init(options); //TODO add callback for error

    return {i18n, i18nMiddleware};
};

the same happens if use order: ['header']

Expected behavior

I was expecting that Language detector will automatically change the language on the request, and that I dont have to manually set changeLanguage

Your Environment

• runtime version: node v12.16.3
  -"i18next": "^19.6.2",
• os: Windows/Linux
• "i18next": "^19.5.3",
  "i18next-fs-backend": "^1.0.7",
  "i18next-http-middleware": "^3.0.2",

[adrai]

Can you please create a reproducable example like here: https://github.com/i18next/i18next-http-middleware/tree/master/example/basic so I can run it?