Variabile de Sesiune

Nu pot seta o a doua variabila de sesiune si nu inteleg de ce:

session_start();
	function get_string_between($string, $start, $end){
				.....
				return substr($string, $ini, $len);
			}
			if(isset($_POST['inputEmail']) && isset($_POST['inputPassword']) && $_POST['inputEmail'] != '' && $_POST['inputPassword'] != ''){
				// ceva cod ...
						$user_json = json_encode($value);
						$user_json = json_decode($user_json, true);
   $user_json2 = json_encode($value);
						$user_json2 = json_decode($user_json2, true);
						$fullName = get_string_between($user_json['dn'], "CN=", ",OU");
						if($fullName != ""){
							$fullName = $fullName . "rrererer";
							$_SESSION['user'] = $fullName;
							$dept = get_string_between($user_json2['dn'], ",OU=", ",OU");
							$_SESSION['dep'] = "dewnjedjnjen";
							error_log(get_string_between($user_json2['dn'], ",OU=", ",OU"));
							header('Location: URL');
							session_write_close();
							exit();
						}
						else{
							$_SESSION['user'] = $username;
							header('Location:URL');
							exit();
						}
					}
				}
				else{
					header('Location:URL');
				}
			}
			else{
					header('Location: URL');
				}

Variabila de sesiune 'user' este intodeauna setata, in schimb pentru dep chiar de scriu un string "abcd" nu e setata.
Primesc doar Notice: Undefined index: dep

posteaza si tu codul indentat corect si cat de cat functional (in loc de "......." puteai pune "// bla bla")

Si nu se vede unde incerci sa accesezi dep

fara session_write_close ai incercat?

$user_json = json_encode($value);
				$user_json = serialize($user_json);
				$fullName = get_string_between($user_json, "CN=", ",OU");
				$departament = get_string_between($user_json, "OU=", ",OU=") . ""; 
				if($fullName){
					$_SESSION['departament'] = $departament;
					$_SESSION['user'] = $fullName;
				   
				}
				elseif($fullName == ""){
					$_SESSION['user'] = $username;
					$_SESSION['departament'] = "Fara Departament";
				   
				}
			}
		}
	}
   
	header('Location: http://localhost/Netbeans-Projects/PROJECT-TO-DO/index.php');
	exit();

Varianta aceasta de final ruleaza bine. Era o problema de logica. Nu stiu care sigur, dar e destul de ciudat PHP-ul fata de Java.