p:repeat inside of p:dashboard to iterate over panels

I use PF 5.3.5 and Mojarra 2.2.8.

<p:dashboard id="dashboard" model="#{customAttributesSettings.model}" disabled="#{!customAttributesSettings.editable}" styleClass="positionPanelContainer positionPanelBox positionedPanelBoxR">
   <p:ajax event="reorder" listener="#{customAttributesSettings.changed}" update="@form" />
   <p:repeat var="column" value="#{customAttributesSettings.availableColumns}" offset="" size="" step="" varStatus="">
      <p:panel id="locked" header="Locked">
         <p:selectBooleanCheckbox partialSubmit="true" value="#{column.selected}" disabled="#{!customAttributesSettings.editable}" valueChangeListener="#{customAttributesSettings.selectionMade}" />
         <h:outputText value="#{column.name}" style="width: 200px;" disabled="#{!customAttributesSettings.editable}" styleClass="columnName#{column.selected ? '' : 'Dis'}" />
         <p:inputText partialSubmit="true" value="#{column.type.width}" disabled="#{!customAttributesSettings.editable}" />
      </p:panel>
   </p:repeat>
</p:dashboard>

I get this error

com.sun.faces.application.view.FaceletViewHandlingStrategy.handleRenderException Error Rendering View[/secure/settings/settings.xhtml] java.lang.ClassCastException: org.primefaces.component.repeat.UIRepeat cannot be cast to org.primefaces.component.panel.Panel at org.primefaces.component.dashboard.DashboardRenderer.findWidget(DashboardRenderer.java:96)

It does not work with the JSF classic ui:repeat component. How shall I do it, please? Thanks in advance.