Session data lost after redirect randomly (CI4.1.5)

Hello people,
Here facing an even worst scenario. I cant simply pass session data from one request to another. $_SESSION array just erases on redirect or when a new page is loaded.
I've tryed every internet solution found, even intalled my app on another fresh server and nothing changes. Just can't make a login page to work... unvelievable.
I've edited session and cookie classes fordebuggin and couldn't find what's going on.
For the record, i've followed this super simple example just to not geting into any trouble, but instead...
Example: https://www.tutsmake.com/codeigniter-4-l...l-example/
Thanks!