$.post() / re-validation after error

[gh59291]

0. useful & powerful library, thx 4 work.

i) i want to check age range from server with $.post action.

ii) Problem :
a) if first test is false -wrong date
b) and second test is good,
c) validator does not reset / perfome test and let form submit

In facts it seems that validation is not processed anymore.
Should i reset form validation before ?

iii) addValidator(s) :

-this works fine-

$.formUtils.addValidator({
    name : 'checkDateBirthHolderJs',
    validatorFunction : function(value, $el, config, language, $form) {
        var age=ageGet(value,'/'); console.log('checkDateBirthHolder='+age);
        var check=true;
        if(parseInt(age)<16){ check=false };
        if(parseInt(age)>45){ check=false };
        return check;
    },
    errorMessage : gloss.badBirthHolder,
    errorMessageKey: 'badBirthHolder'
});

this returns good ajax response but no "re-validation"

$.formUtils.addValidator({
    name : 'checkDateBirthHolderAjax',
    validatorFunction : function(value, $el, config, language, $form) {
        var csrf=$form.find('#csrf').val();
        var check=false;

        $.post( "/myController/dataCheck/", { csrf:csrf, date_birth:value, ac:'date_birth_holder', i18n:app.i18n }, function(rsp,status) { //console.log(rsp);
            var data = $.parseJSON(rsp); console.log(data); console.log(check);
            check=data.valid; console.log(check); //check ok
            return check;
        });

        return check;
    },
    errorMessage : gloss.badBirthHolder,
    errorMessageKey: 'badBirthHolder'
});

iv) using server leads to same problem.

What's wrong ?
Thx for tips & time
gh59291