Cookies notice of Warehouse theme appears 1 second

To avoid the cookie notice to appear 1 second, then disappear, you must override the javascript file of the iqitcookielaw module.

To do it, create a file with the following content:

$(document).ready(function () {
 if (getCookie('cookielaw_module') != 1) {
  $("#iqitcookielaw").addClass('iqitcookielaw-showed');
 }
 $("#iqitcookielaw-accept").click(function (event) {
  event.preventDefault();
  $("#iqitcookielaw").removeClass('iqitcookielaw-showed');
  setcook();
 });
});

function setcook() {
 var name = 'cookielaw_module';
 var value = '1';
 var today = new Date();
 var expire = new Date();
 expire.setTime(today.getTime() + 3600000 * 24 * 14);
 document.cookie = name + "=" + escape(value) + ";path=/;" + ((expire == null) ? "" : ("; expires=" + expire.toGMTString()))
}

function getCookie(cname) {
 var name = cname + "=";
 var ca = document.cookie.split(';');
 for (var i = 0; i != ca.length; i++) {
  var c = ca[i];
  while (c.charAt(0) == ' ') c = c.substring(1);
  if (c.indexOf(name) != -1) return c.substring(name.length, c.length);
 }
 return "";
}

And place it in the theme (or child theme if you have one): /themes/warehouse/modules/iqitcookielaw/views/js/front.js

Then clear the cache in the Performances page.