Primefaces Command Button Ajax Works Only Once

I have the following command button which enters only once in the saveData method:

<p:commandButton id="saveBtn" 
    value="#{messages['um3.common.label.save']}"            
    actionListener="#{advisorBean.saveData}"            
    disabled="#{advisorBean.disabledSave}">             
    <f:param name="positionId" value="#{advisorBean.positionId}" />
</p:commandButton>

Here is the saveDate method signature: public void saveData().

Also, the page containing the button is inserted into a layout and the button sits in a primefaces panel.

Layout Page:

<h:body>
    <p:layout fullPage="true">
       <p:layoutUnit>
            <ui:insert name="footer">

Button Page:

<ui:define name="footer">
            <p:panel id="footer">
                <p:commandButton id="saveBtn" ...

Could you please advise?

Andrei