Object not popule after click in yes in dialog

Question

I am having trouble retrieving the values ​​filled in the form when clicking the yes button in the dialog, the data does not appear filled in the respective objects. What is going on? Didn't I correctly update the button?

Class PostionInformation

public class PostionInformation{

private Box box;
private Position position;

public PostitionInformation(){
box = new Box();
position = new Position();
}

}

Bean public void savwPostionFinish() { Box box = new Box();

        if(this.positionInformation.getBox() != null) {
            box = this.positionInformation.getBox();
        }

        List<Position> list= dao.searchBox(box);

        changeInformation(positions);

    }

public void chanceInformation(List<Position> postions) {
//List empyty
}

form.xhtml

<ui:composition xmlns="http://www.w3.org/1999/xhtml"
                xmlns:h="http://java.sun.com/jsf/html"
                xmlns:f="http://java.sun.com/jsf/core"
                xmlns:ui="http://java.sun.com/jsf/facelets"
                xmlns:p="http://primefaces.org/ui"
                template="/WEB-INF/template.xhtml">


        <h:form id="formMain">

            <p:messages id="messages" showDetail="true">
                    <p:autoUpdate />
                </p:messages>

        <div class="ui-g ui-fluid">

            <div class="ui-g-12">

                <div class="card card-w-title">

                    <p:panelGrid columns="2" layout="grid" styleClass="ui-panelgrid-blank form-group" id="formBox">

                        <p:selectOneMenu id="cbboxBox" value="#{positionMng.positionInformation.box}" 
                                         converter="#{boxConverter}" required="true" 
                                      immediate="true">
                            <f:selectItem itemLabel="#{msg.optionBox}"/>
                            <f:selectItems value="#{positionMng.listaBoxes}" var="box"
                                        itemValue="#{box}" itemLabel="#{box.name}"/>
                         </p:selectOneMenu>

                    </p:panelGrid>

                    <p:panelGrid columns="2" layout="grid" styleClass="ui-panelgrid-blank form-group" id="formSituation">
                        <h:panelGroup>
                            <p:outputLabel for="radioSituation" value="#{msg.labelSituation}" />
                            <p:selectOneRadio layout="responsive" columns="3" id="radioSituation" value="#{positionMng.changeInformation.position.situation}" 
                                            converter="positionSituationConverter" required="true" 
                                           immediate="true">
                                <f:selectItems value="#{positionMng.listSituation}" var="position"
                                              itemValue="#{position}" itemLabel="#{position.name}"/>
                            </p:selectOneRadio>

                        </h:panelGroup>
                    </p:panelGrid>

                     <p:panelGrid columns="2" layout="grid" styleClass="ui-panelgrid-blank form-group">
                         <p:commandButton icon="ui-icon-save" 
                                        value="#{msg.save}" oncomplete="PF('confirmFinish').show()"
                                        process="@this" update=":formMain:finishDialog"
                                        title="#{msg.salvar}"/>  
                         <p:commandButton icon=" ui-icon-closethick" action="#{positionMng.cancel()}" 
                                     value="#{msg.cancel}" immediate="true"
                                     title="#{msg.cancel}"/>

                    </p:panelGrid>

                </div>

            </div>

        </div>

            <p:confirmDialog header="#{msg.messageFinish}" 
                             message="#{msg.messageFinishAlteracaoPosicaoLote} #{msg.mensagemContinue}"
                             widgetVar="confirmFinish" id="finishDialog">
                <p:commandButton value="#{msg.yes}" oncomplete="PF('confirmFinish').hide();"
                                 action="#{positionMng.savePositionFinish()}" process="@this"
                        update=":formMain:formSituation :formMain:formDadosBox" id="yesButton" />
                <p:button value="#{msg.no}" onclick="PF('confirmFinish').hide(); return false;" />
            </p:confirmDialog>


    </h:form>

    </ui:define>

</ui:composition>