Navision LS Retail 2016

Hi all, I am facing a problem in Total Discount of LS Retail.

I have created a Total Discount offer as below :
in Line FastTab :
Type    No        Exclude

Item     A          True
Item     B         True
Item     C         True

Benifits FastTab

Step Amt    Type       No       Value Type
100             Item        D         Amount

Now I scanned on POS as

Item       Price
X            75
B            30

now when I pressed Total, Optional Benifits popup come(with item D)
my understanding is if i exclude item B in Line Fast tab then Benifit Popup should not come.

Then I deleted Type All from Line Fast Tab, now Benifits popup is not coming. but if I select item D with X and B it is not coming with price zero(because in Benifit fasttab i have put this item with value blank.)

where i am doing mistake??