h:selectOneMenu and valueChangeListener

hi guys i have an issue
i use Combobox with h:selectOneMenu and value changeListner

but why when the value in the first comboBox i already change,, value in the second ComboBox wasnt came out,,
this is my code for first ComboBox

<h:panelGroup>
                                        <a4j:region renderRegionOnly="true">
                                            <h:selectOneMenu value="#{harianPenerimaanMBean.compoffices.officeId}" valueChangeListener="#{harianPenerimaanMBean.updatePerwakimName}" required="true" requiredMessage="Pilih Salah Satu" id="perwakim">
                                            <f:selectItem itemValue="" itemLabel="Pilih Kantor Wilayah/Perwakim"/>

                                            <f:selectItems value="#{harianPenerimaanMBean.perwakim}"/>
                                            <a4j:support event="onchange" reRender="kanim" ajaxSingle="true"/>
                                        </h:selectOneMenu>
                                        <h:panelGroup id="msgPerwakim">
                                            <h:message for="perwakim" styleClass="error"/>
                                        </h:panelGroup>
                                            </a4j:region>
                                    </h:panelGroup>

second ComboBox

my Bean

public HarianPenerimaanMBean() {
    
//    layananJpaController = new LayananJpaController();
    compOfficesJpaController = new CompOfficesJpaController();
    compoffices = new CompOffices();
    
perwakim = new ArrayList<SelectItem>();
kanim = new ArrayList<SelectItem>();
jenisPNBP = new ArrayList<SelectItem>();

}

public void updatePerwakimName(ValueChangeEvent event){
                Long compOffices = (Long) event.getNewValue();
//                BigInteger id = new BigInteger(compOffices.toString());
//                System.out.println(id);
                setKanim(new ArrayList<SelectItem>());
//                getKanim().add(new SelectItem("","Semua Kantor Imigrasi"));
                for(CompOffices compOffice : compOfficesJpaController.findCompOfficesEntities()){
                    if (compOffice.getOfficeId().longValue() == compOffices) {
                        System.out.println(compOffice.getOfficeName());
                        getKanim().add(new SelectItem(compOffice.getOfficeId().longValue()));
                    
                    }
                
                
                }

}
            
            
//            
//            public void updatePerwakimName(CompOffices compOffices){
//                Long comOffice  = (Long) compOffices.getOfficeId();
//            getPerwakim().clear();
//            for(CompOffices compOffice : compOfficesJpaController.findCompOfficesEntities()){
//                if (compOffice.getOfficeId() == comOffice){
//                    getPerwakim().add(new SelectItem(compOffice, compOffice.getOfficeName()));
//                
//                }
//            
//            
//            }
//            
//            }
     
            
            
            
            public List<SelectItem> getJenisPNBP(){
    List<SelectItem> jenisPNBP = new ArrayList<SelectItem>();
    jenisPNBP.add(new SelectItem("1","PNBP Imigrasi"));
    jenisPNBP.add(new SelectItem("2","PNBP AHU"));
    jenisPNBP.add(new SelectItem("3","PNBP Deplu"));
    jenisPNBP.add(new SelectItem("4","Non PNBP"));
    
    return jenisPNBP;
    }

public Addresses getAddress() {
        return address;
    }

public void setAddress(Addresses address) {
        this.address = address;
    }

public Biaya getBiaya() {
        return biaya;
    }

public void setBiaya(Biaya biaya) {
        this.biaya = biaya;
    }

public CompOffices getCompoffices() {
        return compoffices;
    }

public void setCompoffices(CompOffices compoffices) {
        this.compoffices = compoffices;
    }

public DetailPendapatan getDetail() {
        return detail;
    }

public void setDetail(DetailPendapatan detail) {
        this.detail = detail;
    }

public List<SelectItem> getJenis() {
        return jenisPNBP;
    }

public void setJenis(List<SelectItem> jenis) {
        this.jenisPNBP = jenis;
    }

public JenisLokasi getJenisLokasi() {
        return jenisLokasi;
    }

public void setJenisLokasi(JenisLokasi jenisLokasi) {
        this.jenisLokasi = jenisLokasi;
    }

public List<SelectItem> getKanim() {
//    List<SelectItem> kanim= new ArrayList<SelectItem>();
    return kanim;
    }

public void setKanim(List<SelectItem> kanim) {
        this.kanim = kanim;
    }

public Layanan getLayanan() {
        return layanan;
    }

public void setLayanan(Layanan layanan) {
        this.layanan = layanan;
    }

public Pendapatan getPendapatan() {
        return pendapatan;
    }

public void setPendapatan(Pendapatan pendapatan) {
        this.pendapatan = pendapatan;
    }

public Permohonan getPermohonan() {
        return permohonan;
    }

public void setPermohonan(Permohonan permohonan) {
        this.permohonan = permohonan;
    }

public List<SelectItem> getPerwakim() {
        
        
            List<SelectItem> perwakim= new ArrayList<SelectItem>();
            perwakim.add(new SelectItem("","Semua Kantor Wilayah/Perwakim"));
                      for(CompOffices com : compOfficesJpaController.findCompOfficesEntities()){
                          if(com.getOfficeType().equals(new BigInteger("2"))){
                    perwakim.add(new SelectItem(com.getOfficeId(), com.getOfficeName()));
                          }
                }
                return perwakim;
        }

public void setPerwakim(List<SelectItem> perwakim) {
        this.perwakim = perwakim;
    }

}

thanks expert gb