What customer lifetime value measures
Lifetime value is what one customer is worth across the whole time they keep buying, rather than on the first order. A store looking only at the first order sets its acquisition budget from the smallest number it will ever have.
There are two versions of it and they are far apart. Gross revenue LTV counts every pound the customer spends. Contribution LTV counts what is left after the cost of the goods. On a 55% margin the second is a little over half the first, and only the second one can pay for anything.
Both appear in the result here, in that order, so the gap between them is visible rather than a matter of which one someone reached for.