Login integration problem

I'm using the following code on my home page to display custom content to users who are logged in on the forum:

$framework_url = 'forum/init.php';

require_once($framework_url);

\IPS\Session\Front::i();
$member = \IPS\Member::loggedIn();

if ($member->member_group_id == $a) {
    //Show member stuff
} else {
    //Show guest stuff
}

When a user visits the forum and then goes to the home page the code correctly reports that the user is logged in, however if a user goes away for a while so that their session expires and then returns to the home page, the code is reporting that they are logged out, even though a visit to the forum afterwards will show that they are actually still logged in.

How do I get the above code to recognize that a user is logged in (like the forum does) even if their immediate session has expired ?

Thank you.