ace:ajax oncomplete not called on ENTER

Question

I need to call a js function to set the focus (alert in my example) after page rerenders, but it looks that oncomplete is only evaluated on click, not on ENTER key press. btw, action is called fine on ENTER.

see following:

<h:commandLink id="lnk" value="link" action="#{bean.search}">
    <ace:ajax execute="@this" onComplete="alert('LINK');" />
</h:commandLink>

<h:commandButton id="btn" value="button" action="#{bean.search}">
    <ace:ajax execute="@this" onComplete="alert('BUTTON');" />
</h:commandButton>

Link works fine on both: click & ENTER, but button works only on click. Any idea how to solve this? Thanks