Problem solved. If someone has this problem,you can verify this:
This was my flow: My service return EntityClass,which i convert into ModelClass inside the controller. When i create/edit something,i actually edit the model,pass it from the view to the controller. Here,i convert the ModelClass to EntityClass and sent it to the service. The problem is that the validator triggers only when i reach the service. In fact, my service was expecting an EntityClass and i was validating a ModelClass. I modified the code,so the service now expects a ModelClass and i do the conversion right here,not in controller anymore. So,the problem was the fact that i was converting from model to entity before validating.