WooCommerce adds automatically items to shopping after refreshig

my problem is that in woocommerce when I’m on a product detail site I add items and after refreshing the browser woocommerce sends new data and adds items automatically to shopping cart. For example when I add 2 items after refreshing there are 4, 6, 8 and so on items displayed in shopping cart.

Here you can test it and see it in the right footer widget: https://tinyurl.com/p4fovpe

Any suggestions?

Greets, Peter