Grand total not update automatically Magento 1.9

Well, I created a discount coupon. When I use the coupon code, this is applied perfectly, but the Grand Total not update until refresh the page.

The Ajax execute perfectly and the response is correct. See the next img.

With the code applied, before refresh the page. enter image description here

With the code applied, after refresh the page. enter image description here

In here cancel the coupon and not update the Grand Total, but disapear the discount. enter image description here

See the reviewAction response. The amount in the response is not the same as in the total shown.

Where is the issue? thanks in advance.

PD: My store is in Spanish.