frumpish

Hello, We are using prestashop 1.7.2.0 with classic theme. Sometimes random orders are split into two orders. ( Causes customers to pay shipping payment twice.) So we have been facing this problem for a while now. We couldn't come up with any solutions yet. There is no correlation between the products in the orders or any other shipping settings other than free shipping for 150 € and above. There are two shipping options (local and international) but there is no shipping restrictions. I've been searching for a reason and a solution but nothing seems to be related with this problem. Yesterday something weirder happened. An order was split into two again but one of the orders only had 1 product in it (34.90 €) and its total price was much larger than the product. Any ideas about what might be the reason behind this?