PHP / Laravel - update values of JSON object

In Laravel PHP I have an object which needs some parameters updating. The object is updated and I can return or dd() the correct values. But when I ->save() its as if the values haven't been changed. The ->save method works fine, but the way I'm updating the object values is obviously wrong somehow...

So using the following code I loop through an array of parameters to update and create an updated object :

      $account = Account::find('account_id');
      // ^returns something like (object)['user'=>['name'=>'jeff','age'=>'20']];

      $to_update = ['user.name':'john', 'user.age':'50'];

      // the following function converts exploded arrays of key names to php objects
      // ie user.name:"John" becomes user->name = john
      function get($path, $object, $value) {
        $temp = &$object;
        foreach($path as $var) {
            $temp =& $temp->$var;
        }
        $temp = $value;
      }

      // $account->user->name = "jim";
      // $account->user->age = "100";

      foreach($to_update as $keys => $value){

        $key = explode(".", $keys);
        get($key, $account, $value);
      }

      // $account->save();

      return $account;

This returns a nice, updated object like :

+"user": +"name":"john" +"age":"50"

HOWEVER if I save that object, it doesn't save the updated values, only the old values. So changing the last two line :

      $account->save();

      return $account;

results in

+"user": +"name":"jeff" +"age":"20" // these are the old values

So my question is - why does return $account give the correct, updated object, but $account->save(); return $account revert to the original values?

FYI: the following code works (but is too simple for my purposes) :

  $account = Account::find('account_id');
  // ^returns something like (object)['user'=>['name'=>'jeff','age'=>'20']];

  $account->user->name = "jim";
  $account->user->age = "100";

  $account->save();

  return $account;

+"user": +"name":"jim" +"age":"100"

via Chebli Mohamed