The price shown is wrong

Open the upsell and click Save. The offer card's prices and product names are captured when you pick the product, and a re-save is what refreshes them.

This affects what the customer sees. What they are charged is worked out separately, and in most cases is already correct — see below.

Why the shown price goes stale

When you add a product to an offer, Hype stores its title, price and image with the upsell so the offer can render instantly at checkout without fetching them again. Change the price in Shopify afterwards and the stored copy keeps the old number until the upsell is saved again.

You see this as:

a struck-through "was" price that is no longer the product's price
a discounted "now" price computed from that old price
an old product name on the card
the same wrong values in the Preview panel in the form

Products where you left All variants selected are read live at offer time and are not affected. It is products pinned to a specific variant that carry the stored price.

What the customer is actually charged

Percentage off — applied to the product's real, current price at the moment of acceptance. Correct even with a stale card.
Set product price — the discount is worked out from the product's live price when the customer accepts, and is skipped entirely if the target price is not below it. Correct, but the card may have advertised a different saving.
Amount off — the fixed number you entered, off the real price.
On the Checkout surface, the discount is calculated by Shopify against the live line total, so it is always based on current prices.

In short: a stale capture usually shows the wrong saving rather than charging the wrong amount. Fix it anyway — an offer that advertises a price the customer is not charged is a support ticket either way.

Fixing it

Open Hype Upsell and click the upsell's name.
If the product's variants changed, click the pencil on that product row and reconfirm the selection.
Click Save.

Saving re-reads the product and stores its current title, price and image. Do this after any price change, rename, or variant change on a product an upsell offers.

Prices in a different currency

Amount off and Set product price are single numbers in your store's currency, used as-is in whatever currency the customer is paying in — there is no conversion. On a store selling in several currencies a "10 off" is 10 units of the buyer's currency, which is not the same value everywhere.

Percentage off is unaffected and is the right choice for multi-currency stores.

The set price seems to be ignored

Set product price never raises a price. If the price you entered is equal to or higher than the product's current price, no discount is applied and the product is offered at its normal price. Check the product's current price in Shopify and lower the set price below it.

The same guard applies to Amount off on the checkout surface: a discount larger than the line total is capped at the line total, never past zero.

The preview shows different prices from checkout

The Preview panel in the form is a mock drawn from your saved configuration, not a live render — real checkout extensions cannot run inside the Shopify admin. It uses the stored prices, and it has no order, so it shows no shipping or taxes. Use it to check layout and copy, and a real test order to check money.

The post-purchase totals show a dash

On the post-purchase page, Subtotal, Shipping, Taxes and Total are calculated by Shopify a moment after the page opens and show — until they arrive. If they never resolve, the discount badge still describes the offer and accepting still charges the correct amount — the totals are display only.