By default, the side cart and the cart summary at checkout show the price of the product without indication of discounts.
You can change this in your CheckoutWC settings.
Show Sale / Discount prices in the Side Cart
- Go to WP Admin > CheckoutWC > Side Cart
- Check the box next to ‘Enable Sale Prices’
- Click ‘Save Changes’ in the top right
Show Sale / Discount Prices in the Checkout Cart Summary
- Go to WP Admin > CheckoutWC > Cart Summary
- Check the box next to ‘Enable Sale Prices’
- Click ‘Save Changes’ in the top right