I have created a custom benefit/action for a promotion. When user applies the promo, nothing happens. There are no errors when i check in debug. The code is hit though.

public void Execute(IRuleExecutionContext context)
{
    .....code
    ......
    ApplyDiscountPercentForLineItems(commerceContext,  validCartLineItems, discountPercent, awardingBlockName);
}

public static void ApplyDiscountPercentForLineItems(CommerceContext commerceContext, List<CartLineItem> validCartLineItems, decimal discountPercent, string awardingBlockName)
{
   var cart = (commerceContext.Objects.OfType<Cart>()).FirstOrDefault();
   var totals = (commerceContext.Objects.OfType<CartTotals>()).FirstOrDefault();

   var model = commerceContext.Objects.OfType<PropertiesModel>().FirstOrDefault();
            
   foreach (var line in validCartLineItems)
   {
     var discount = commerceContext.GetPolicy<KnownCartAdjustmentTypesPolicy>().Discount;
     var d = discountPercent;
                
     if (commerceContext.GetPolicy<GlobalPricingPolicy>().ShouldRoundPriceCalc)
     {
       d = decimal.Round(d, commerceContext.GetPolicy<GlobalPricingPolicy>().RoundDigits, commerceContext.GetPolicy<GlobalPricingPolicy>().MidPointRoundUp ? MidpointRounding.AwayFromZero : MidpointRounding.ToEven);
     }

    decimal amount;    
    var currentAmount = totals.Lines[line.Id].SubTotal.Amount;    
    amount = currentAmount - (currentAmount * d / 100);
    amount = amount * decimal.MinusOne;
    totals.Lines[line.Id].SubTotal.Amount += amount;
                
    var item = new CartLineLevelAwardedAdjustment
    {
      Name = (string)model.GetPropertyValue("PromotionText"),
      DisplayName = (string)model.GetPropertyValue("PromotionCartText"),
      Adjustment = new Money(commerceContext.CurrentCurrency(), amount),
      AdjustmentType = discount,
      IsTaxable = false,
      AwardingBlock = awardingBlockName,
      IncludeInGrandTotal = true
    };

   line.Adjustments.Add(item);

   line.GetComponent<MessagesComponent>().AddMessage(commerceContext.GetPolicy<KnownMessageCodePolicy>().Promotions, $"PromotionApplied: {model.GetPropertyValue("PromotionId")}");
            }           
        }