ContentCollection not selectable

Using Neos & Flow
10

Sorry, but its not working for me.

I tryed this:

Fusion:

prototype(XY.xy:Panel) < prototype(TYPO3.Neos:Content) {
  templatePath = 'resource://XY.xy/Private/Templates/TypoScriptObjects/Panel.html'
}

prototype(XY.xy:Accordion) < prototype(TYPO3.Neos:Content) {
  templatePath = 'resource://XY.xy/Private/Templates/TypoScriptObjects/Accordion.html'
  panelCollection = TYPO3.Neos:ContentCollection {
    nodePath = 'panelCollection'
  }
}

NodeTypes.yaml

'XY.xy:Panel':
  superTypes:
    'TYPO3.Neos:Content': true
  ui:
    label: 'Panel'
    icon: 'icon-folder-close'
    group: 'general'
  childNodes:
    content:
      type: 'TYPO3.Neos:ContentCollection'
      constraints:
        nodeTypes:
          'XY.xy:Panel': false
          'XY.xy:Accordion': false
'XY.xy:Accordion':
  superTypes: 
    'TYPO3.Neos:Content': true
  ui:
    label: 'Akkrodion'
    icon: 'icon-reorder'
    group: 'general'
  childNodes:
    panelCollection:
      type: 'XY.xy:PanelCollection'
      constraints:
        nodeTypes:
          '*': FALSE
          'XY.xy:Panel': TRUE
'XY.xy:PanelCollection':
  superTypes:
    'TYPO3.Neos:ContentCollection': TRUE

Templates:

Panel.html
{namespace neos=TYPO3\Neos\ViewHelpers}

<div class="panel panel-default">
   <div class="panel-body">Hallo</div>
</div>

Accordion.html
{namespace ts=TYPO3\TypoScript\ViewHelpers}

<div>
    <div  role="tablist" aria-multiselectable="true">
        {panelCollection -> f:format.raw()}
    </div>
</div>

I have no idea whats wrong. :’(

All other contentcollections work and I habe no additional NEOS css…

Any ideas where I can look for?