Error: Prices not displayed correctly

Hi,
We have a problem with the prices in the plugin.
We have a page https://www.silly-doh.dk/erhverv which display B2B products, and the prices here are shown without tax.

But on some of the products, the price is displayed as a discount price. So we have the original price (without tax) showed with a line across and then underneath we have the correct price – Like it’s a sale item, which isn’t correct.

This only happens on some of the products and the settings are exactly the same. We don’t want to display the items as sale items with a sale price.

Can you help telling why this happens? And how do we fix it?

The page I need help with: [log in to see the link]