Checkbox ajax event not triggerd

I have the following code that is not working.

<p:selectManyCheckbox id="make" value="#{priceList.searchMakeId}"   >
                                <p:ajax event="click" process="@form" update="recordCountPanel" immediate="true" listener="#{priceList.reCountRecords}" />
                                <f:selectItems value="#{priceList.vehicleMakeItems}" />
                            </p:selectManyCheckbox>

Bean method

public void reCountRecords() throws MWSException {

The method is never called. When I replace the p:selectManyCheckbox with h:electManyCheckbox or with p:selectManyMenu Then when clicking/changing these components, the bean method is called.

I can't find in the generated shtml source any onlclick or onchange event on the primefaces checkbox.

So I'm guessing something is not rendered correctly when I use p:selectManyCheckbox

But since I don't have any errors on my server or in browsr javascript I'm clueless of what is causing the problem. I tried with primefaces 6.0 6.1.6 and 6.1.8 . All the same result. Any ideas?