primefaces selected item highlight problems

Question

I have a form in which there are two buttons - "button" and "button1" and a split button. The actionListener methods just update the message content.

1. When button1 is clicked, only growl is updated. After that if I move mouse over split button items, the selected item gets highlighted.

2. When button is clicked, whole form is updates. After that if I move mouse over split button items, the selected item does not get highlighted.

   This issue was not there in primefaces 3.5 but is there in primefaces 5.0.

Sample code:

<h:form>
    <p:growl id="messages" />
    <p:commandButton value="Button" actionListener="#{tryBean.save}" update="@form"/>
    <p:commandButton value="Button1" actionListener="#{tryBean.save}" update="messages"/>
    <p:splitButton value="Save" actionListener="#{tryBean.save}" update="messages" icon="ui-icon-disk">
       <p:menuitem value="Update" actionListener="#{tryBean.update}" update="messages"    icon="ui-icon-arrowrefresh-1-w" />
       <p:menuitem value="Delete" actionListener="#{tryBean.delete}" ajax="false" icon="ui-icon-close" />
       <p:separator />
       <p:menuitem value="Homepage" url="http://www.primefaces.org" icon="ui-icon-extlink" />
    </p:splitButton>
</h:form>

Thanks