$_SESSION working after second log-in - php

Question

Hello I have a strange issue, where I have a log-in page index.php: in which log-in page I am setting:
$_SESSION['user'] = $row['username'];
for users which have been logged in successfully.
Then on the landing page I have a check to see if user is logged in, if not to be redirected to the log-in page:
if(!$session->is_loggedin()) {
// session no set redirects to login page
$session->redirect('index.php');
}
Inside the class file:
public function is_loggedin() {
if(isset($_SESSION['user'])) {
return true;
}
}
So the problem which I am facing is presented only on the internet server on the local host xampp everything works fine. Problem is if I log-in to the site. then If do log out and type the log-in URL I am getting redirected to the home.php where I am making a print_r($_SESSION) and it shows that there is session in the array like the session still exists. but when I click on any links on the menu I am send back to log-in page without a session.
and have to log-in.
code on the index.php page to check if session exists:
if($login->is_loggedin()!="") {
$login->redirect('home.php');
}
So in this case every time a user comes to the page it shows like he is logged in but it is not and then he can see the home.php which is supposed to be protected. Once a user click on any menu link it get's redirected to the log-in page.
I guess it might be some php configuration since on the localhost XAMPP is working. Any idea where I have to look ?
EDIT: I have placed the following check on the index page:
if(isset($_SESSION['user']) && !empty($_SESSION['user'])) {
echo 'Set and not empty, and no undefined index error!';
}
to check if there is a session , so each time when I open the URL it shows TRUE. when I open /home.php it opens home page clicking on any links redirected to home page where it does not echo anything. It feels like the server is caching the first page with session each time when I open it. or the browser automatically is sending this information to the server.
Or another case scenario which is experienced sometimes is. I am opening the site and getting logged it. clicking any button I am redirected to log-in page after second log-in attempt everything works just fine.
Another thing that occures is that when a fake session is established all the Bootstrap Glyphicon are showing squares instead of actual icons
I see that the in php info session.use_only_cookies is set to ON maybe this is the issue.

Answer 1

for starters, your login check,
if($login->is_loggedin()!="")
{
$login->redirect('home.php');
}
why is this not if($login->is_loggedin()!== true)
This would take out any strange returns on the if check,
Currently if it sees anything that is not "", it will not redirect to home, ie. if your function returns false.
Thats the main thing that stands out to me, (i may be way off base here)