Непонятное поведение localStorage

localStorage.setItem("cacheAaaaaa", JSON.stringify({ l:2, t:123})); 
localStorage.setItem("cacheBbbbbb", JSON.stringify({ l:3, t:1543001789})); 
localStorage.setItem("cacheCccccc", JSON.stringify({ l:4, t:234})); 
localStorage.setItem("cacheDddddd", JSON.stringify({ l:5, t:345})); 
localStorage.setItem("cacheEeeeee", JSON.stringify({ l:6, t:456})); 
localStorage.setItem("cacheFfffff", JSON.stringify({ l:7, t:1543001789})); 
localStorage.setItem("cacheGggggg", JSON.stringify({ l:7, t:567})); 
 
maintenanceStorage(); 
//listStorage(); 
 
function maintenanceStorage() { 
  for (var n = 0; n < localStorage.length; n++) { 
    var key = localStorage.key(n); 
    if (key.substring(0, 5) == "cache") { 
      if ((Math.trunc(Date.now()/1000) - parseInt(JSON.parse(localStorage.getItem(key)).t)) > 172800) { 
        console.log("Item removed: " + key); 
        localStorage.removeItem(key); 
      } 
    } 
  } 
} 
 
function listStorage() { 
  for (var n = 0; n < localStorage.length; n++) { 
    console.log(localStorage.key(n)); 
    console.log(localStorage.getItem(localStorage.key(n))); 
  } 
}