NextJS i18next not working with defaultLocale

Question

I have deployed the website to DigitalOcean, having 3 i18n languages and the default locale definition. Unfortunately, the website's default (index) path https://somewebsite.com does not work and requires using at least one locale from which it supports:

https://somewebsite.com/en
https://somewebsite.com/es
https://somewebsite.com/fi

Here is my next-i18next.config.js configuration.

module.exports = {
    i18n: {
        defaultLocale: 'en',
        locales: ['en', 'es', 'fi']
    }
};

Is there a chance this 404 Not Found error somehow be fixed?