Can I ask how you applied the sale prices so that they only show up in the cart? While Prestige is a third party developed theme, many of the same principles would still apply for features like this.
Applying the sale price from this tutorial should have it apply on the product and collection page, so I’m curious if you did apply it this way, why it would be appearing only in the cart.
If this isn’t how you applied it and are still seeing issues, it might be worth reaching out to the theme developer directly to see what’s going on. I use Prestige for my store also, and the Maestrooo team have fantastic support. You can reach out to them from the link here. They could also assist you with figuring out how to apply or even apply the code for you. Hope this helps!