Still having trouble with "," and "."

Dear @Emre, I configured both screens in regional settings in windows:

so when I try to add a discount:

If I invert the “,” and “.” in both configuration…

This is the rule I am using:

and of course, when I change the “,” and “.” I also change the \, or \. in in:


This seems to me a strange behaviour, and I cannot remember now why I am writing this, but I had some trouble… as soon as i comes back to my mind, I will add it to this post…