Spring Security 302 redirection after primefaces commandbutton ajax failure on register page

I have a problem with Spring Security and ajax request of primefaces commandbutton. After clicking commandbutton in my signup page and fail response, for next clicking, error 302 occured and return login page! I use primefaces 8.0 and spring security 5.

here is my security config:

<http auto-config="true" use-expressions="true">
    <access-denied-handler error-page="/accessDenied.xhtml"/>
    <form-login login-page="/login.xhtml"
                login-processing-url="/login"
                password-parameter="password"
                username-parameter="username"
                authentication-failure-url="/login.xhtml?error=true"/>
    <logout invalidate-session="true"
            logout-success-url="/"
            logout-url="/logout"/>
    <intercept-url pattern="/login.xhtml" access="permitAll"/>
    <!-- RESOURCES -->
    <intercept-url pattern="/skins/**" access="permitAll"/>
    <intercept-url pattern="/css/**" access="permitAll"/>
    <intercept-url pattern="/adf/**" access="permitAll"/>
    <intercept-url pattern="/images/**" access="permitAll"/>
    <intercept-url pattern="/js/**" access="permitAll"/>
    <intercept-url pattern="/javax.faces.resource/**" access="permitAll"/>
    <intercept-url pattern="/signup.xhtml" access="permitAll"/>
    <intercept-url pattern="/**" access="isAuthenticated()"/>
    <csrf/>
</http>

my signup.xhtml page :

<h:body class="blue-grey-theme">

<h:form id="form" prependId="false">
    <input type="hidden" name="${_csrf.parameterName}" value="${_csrf.token}"/>

            <p:growl id="smsGrowl" life="7000" globalOnly="true"/>

            <p:tabView id="applicantTab" widgetVar="tabView" effect="fade"
                       activeIndex="#{applicantSignUpBean.applicantSignUpModel.tabViewActiveIndex}"
                       style="margin-bottom:10px; text-align: right; width: 98%; min-width: 400px">

                <p:tab id="PersonalTab" title="#{bundle.personal_applicant}">
                    <h:panelGrid id="personalGrid" columns="4" cellpadding="5" style="width: 99%;"
                                 styleClass="ui-grid">

                        <app:outputLabel rendered="true" value="#{bundle.firstName}" required="true" for="fName"/>
                        <app:input id="fName" required="true" requiredMessage="#{bundle.firstname_required}"
                                   value="#{mySignUpBean.mySignUpModel.firstName}"
                                   style="width:250px"/>

                        <app:outputLabel rendered="true" value="#{bundle.lastName}" required="true" for="lName"/>
                        <app:input id="lName"
                                   value="#{mySignUpBean.mySignUpModel.lastName}"
                                   required="true" requiredMessage="#{bundle.lastname_required}"
                                   style="width:250px"/>

                    
                    <!-- ...... -->

                    </h:panelGrid>

                    <br/>
                    <p:outputPanel style="text-align: center; ">
                        <p:commandButton id="btnSavePersonal"
                                         actionListener="#{applicantSignUpBean.signUpPersonal}"
                                         icon="fa fa-save" value="#{bundle.registration}"
                                         process=":form:applicantTab:PersonalGrid  @this"
                                         update=":form:applicantTab:PersonalGrid"
                                         style="margin: 20px; width: 150px;" styleClass="button_save">

                        </p:commandButton>
                        <p:tooltip for="btnSavePersonal" value="#{bundle.save}"/>

                    </p:outputPanel>


                
                </p:tab>
            </p:tabView>

</h:form>

I tried several things but without success...

thanks for your help