Why am I missing input values when opening and closing an iframe using Javascript?

Context: I have an application that uses php + html + css + '"> jquery ). In it I have a page called principal.php that contains an iframe: <iframe src=pedido.php/> within calling pedido.php , as we can see. Inside the page pedido.php I have several <input type=text> and have a specific one that I want to fill with data, next to it we have a lupa that when clicking on it I execute the following javascript function:

function buscaIndicou(id_elemento){
  var parametros = "?disablebuttons=true";
  var width          = $(window).width()+"px";
  var height         = $(window).height()+"px";
  var $div           = $("<div />", { "class":"overflow-box"}).css({"width":width,"height":height});
  var $close         = $("<div />", {"class":"close"}).click(function(){
    $('.overflow-box').remove();
    $('.modal').remove();
    $('.close').remove();
    if (getCookie("IDPessoaModal") == "")
        alert("Ocorreu um erro ao selecionar a Pessoa, tente novamente.");
    else{
      var id  = getCookie("IDPessoaModal");
      var nm  = getCookie("NMPessoaRel");
      var ele = getCookie("TargetEdit");
      $('#'+ele).val(nm);
      $('#'+ele).attr('data-id',id);
      deleteCookie("BuscaDoPedido");
    }
  });
  $('#pnlContent').append($div);
  var html  = '<div class=modal>'+
              '<iframe width="987" height="426" frameborder="0" scrolling=no src="listapessoa.php'+parametros+'" id="mainFrame">'+
              '</div>';
  $('#pnlContent').html($('#pnlContent').html()+html);
  $('.modal').append($close);
}

This code opens a <iframe> on my screen with a modal look, so I go there and pick a Person from the list, save the cookies that I use there after in the event of click() of div.close and then click on div.close that gives .remove() to everything I've created.

Problem: When the elements that I created are removed, and I see my <input> and the magnifying glass, the information is loaded to it correctly, however, all other <input> which I have filled, are empty.

Why were they empty if I did not reload or close <iframe src=pedido.php> and just created another <iframe> inside it after I closed it?

I'm sure there's no problem with PHP or HTML code, so I did not post anything, but if you insist I can try to create a similar example because my PHP + HTML code is difficult to understand and is huge. / p>