Issue with discount coupon on ceck out

Hi,
I notice this problem.

I created a discount coupon only for one specific access level so i set "Custom".
I set a minimum order value to 50 Euro.
I set a discount percentage of 10%.

Now i am on check out process with:

5 products x 5 Euro = 25 Euro
Here i have not the discount; that's good

I update the quantity to 11 products = 55 Euro
I click on "Refresh" and the system give me the discount.
That is good too.

I update the quantity to 9 products = 45 Euro
I click on "Refresh" and .... the system give me a message "The cart is empty"
What's wrong?

Excuse me,
I was on my test site and I worked on no update Hikashop version.
Now I update it and the issue is fix
Thank
I'm sorry!