Session not stored (memcached)

Hi!

I have a problem with reading the data from session (using memcached). So I am developing a chrome app which is created with pure HTML + JS (AngularJS). This app is sending the requests to the backend (PHP CI 3), for specific tasks (login, register, logout, ...). Maybe worth of mention is that I am using the Async chrome.storage to save some data directly on client. Everything works fine while using the Chrome app.
Because I want to run that app also on Android, I need to replace this chrome.storage with synchronous window.localStorage which can be used in every webpage. So that is the only difference between them.
So if I want to test this app/webpage with window.localStorage I need to run it like a normal page obviously, and not like the Chrome app. So I am running this with "grunt serve" method which creates some server that is running that page on http://localhost:9000/#. So If I send the request to the server now from that webpage, the session is stored and read properly at the first request. But when I send the second request, the session is lost.

Do anyone have a clue what can be wrong here? Or at least how can I debug this memcached session data?

Thank you very much in advance!