No calculation for offers with 0,5 quantity

Hello,

I have a problem with offers I create. We charge Persondays, and if a consultant is only a half day booked, i want to change the quantity to 0,5 (like in the picture). Everything works fine execpt the “Gesamtpreis” in den last row doesnt show any value excepts 0,00.

We use “,” bcs were in Germany. In the bottom every works just fine, like every other offer with more or equal the quantity of one.

Can someone help me?

Best regards