Problem when adding quantity in webshop

[korter]

I have strange problem when trying to add quantity to shopping cart. When i go to product description page and try to add for example 2 of the same item, when i click on the arrow to make quantity , the product image being changed to another product and some description fields are getting duplicated. And weird is that the page partially reloads and its starting to show the product which is the last one in the order Related products.

 

product description

 

here if you click on the arrow to make quantity 2, you will see that the product image will be changed and it will start to show  another product . And this product is the last one in the Related products order, on the same page  (Check other similar products)

In order to avoid this, i have to remove all Related products from the page and also disable Product comments, because when opening product page, product comments also being changed to another model description in the same page.

 

What could make this problem? 

 

 

Edited November 8, 2018 by korter
link changed (see edit history)

[korter]

Update:

 

i have removed this block from the  product.tpl  and now when adding quantity , it refresh the page and seems that part working fine

 

              {block name='product_refresh'}
                <input class="product-refresh ps-hidden-by-js" name="refresh" type="submit" value="{l s='Refresh' d='Shop.Theme.Actions'}">
              {/block}

 

But my second problem remains, When i open any product page,  where product comments are Enabled,  i can see that product comments are showing for another product, So its mixing products .

 

What to do ? Please someone can help me?