Discounts were combined although settings did not allow to

An automatic 10% discount is giving by subscribing to my newsletter - via Omnisend. The discount code cannot be combined with sales. As the box is not ticked in the settings

this weekend I put some items on sale. A customer bought an item and was able to buy the item with the sale price AND use the discount code. Which should not be possible.

How to fix this issue?

Hi @fransjesophie ,
Can you kindly share your store link (with the password, if any) with us? We will check it and suggest you a solution if possible.