title: Prestashop 1.7.7.8 Ajax cart doesn't update when Add to cart buttons are clicked
body: <p>We are working on a Prestashop website with Prestashop 1.7.7.8, first we tried a theme called Akira, and after a few days we finally changed it to Warehouse theme.</p>
  <p>The problem started when we changed the theme. Have tried also with the Classic Theme, and doesn't work either.</p>
  <p>When you click any &quot;Add to cart&quot; button, the button shows a spinner for 1 second, then nothing happens. If you refresh the page, then the cart item count is increased by 1 unit, which is right, but need to update without refreshing.</p>
  <p>If you click on the cart icon, the dropdown opens, but you can't delete any item, the trash button doesn't work. But if you decrease the quantity of that product, the change is saved (the cart item count doesn't update, anyway, until you refresh the page, but when you reload, the unit is decreased).</p>
  <p>We have tried with various PHP versions: 7.4, 7.3, 7.2... nothing seems to work. Also, the PS cache is disabled and deleted between every attempt.</p>
  <p>Tried a few times to disable all modules in the module manager section, also have checked the options of overrides, disabling it, and the non-native modules in the performance section didn't help anyway.</p>
  <p>When we run in debug mode, nothing strange appears. In the Chrome inspector, there isn't any javascript error (only some yellow warnings about js.map missing files).</p>
  <p>Anyone to help, please?</p>