I found how to display correctly the content. I added a panel and I refreshes it instead of the layout.
<p:commandLink update=":myPanel" actionListener="#{sidePviewTest.sideBarAction}" value="Center1">
<f:param name="pageViewId" value="center1" />
</p:commandLink>
<p:layoutUnit id="center" position="center">
<p:panel id="myPanel">
<ui:include src="#{sidePviewTest.includedPage}" />
</p:panel>
</p:layoutUnit>