overlaypanel primefaces doesnt work fine inside dialog inside tabview - primefaces

Question

I use the dynamic overlayPanel of primefaces inside one p:tab inside one p:dialog like this :
<p:dialog id="dialog" modal="true" header="Nouveau Article"
widgetVar="dlg">
<h:form prependId="false" enctype="multipart/form-data">
<p:tabView id="monpanel">
<p:tab id="tab1" title="Informations">
....
</p:tab>
<p:tab id="tab2" title="Prix">
....
</p:tab>
<p:tab id="tab3" title="Stock et fournisseurs">
<h:outputLabel value="" /><h:outputLabel value="" /><h:outputLabel value="" />
<p:commandButton id="carBtn" value="Selectionner Fournisseurs" type="button" />
<p:overlayPanel appendToBody="true" my="left top" id="carPanel" for="carBtn" hideEffect="fade"
dynamic="true">
<p:dataTable id="table" var="car" rowKey="#{car.fournisseurId}"
value="#{articlesMB.listfournisseurs}" selection="#{articlesMB.selectedFournisseurs}"
rows="10" paginator="true" >
<p:column selectionMode="multiple" style="width:20px" />
<p:column headerText="Id">
<h:outputText value="#{car.fournisseurId}" />
</p:column>
<p:column headerText="Nom">
<h:outputText value="#{car.personne.nom}" />
</p:column>
</p:dataTable>
</p:overlayPanel>
</p:tab>
</p:tabView>
<p:commandButton id="article-ajouter"
update=":messages monpanel :articlesdata"
action="#{articlesMB.ajouter}" value="add" />
</h:form>
</p:dialog>
in the first time it works fine, but when I click on the add button and the validation failed (for any cause) and I click on dynamic button of overlaypanel, it appears but when I check or uncheck one of rows of datatable it disappear, I don't know the cause
do you have any idea how to resolve this problem

Answer 1

You cammandButton should use 'process' attribute, you specify component to submit info(not specify overlay).
For ex:
<p:inputText id="txttest" required="true" value="" />
<p:commandButton process="txttest" id="article-ajouter"
update=":messages monpanel :articlesdata"
action="#{articlesMB.ajouter}" value="add" />

Answer 2

The reason your overlay panel only works once is because you update the panel that holds the command button that overlayPanel is attached to.
It is a bug in overlayPanel emerged after PF 5. You can fix this without resorting process attribute, I think solutions like this reduces the readability of the code.
If you define a widgetVar to overlayPanel, say 'carPanelWDG', and call PF('carPanelWDG').loadContents() function in the onComplete event of the command button everything just works. And even if there is no comment explaining the reason why you did such a thing, anyone can interpret this easily.