By default, cart-level discount is enabled on your WEB POS. This setting allows you to give discount over all the products in the cart.
To disable the setting, please follow these steps:
Open the left-side menu by clicking on the three stripe lines on the top left corner

Click on Settings and select "CARTS" tab

Disable the "Allow cart-level discounts"

To give discount over all the products in the cart, please read our article on How to Apply Cart-level Discount.