TYPO3 Core

There are tow page types configured (the second for ajax calls):

routeEnhancers:
  PageTypeSuffix:
    type: PageType
    default: '.html'
    map:
      '.html': 0 
      '.json': 9876

Now there is a form which creates the ajax url:

<f:form pluginName="Contact" controller="Contact" action="create" name="contact" object="{contact}" pageUid="1" pageType="9876">

If "pageUid" is set to 1 (root page), the call doesn't resolve to the ajax page type. Generated URL in this case is:

/index.json?tx_myext_contact[action]=create&cHash=439fdf59e0347b592dc634fc61b1f871

But if "pageUid" is set to 7 (or any other page, but not root page itself), the call corryctly resolves to the ajax page type. Generated URL ins this case is:

/kontakt/impressum.json?tx_myext_contact[action]=create&cHash=60e3a054b7228703f8ab3d0d385063cb

Having no RouteEnhancers at all, everything (default page type + ajax page type) work fine as expected.

I don't know if this is caused by a misconfiguration with the RouteEnhancers on my side. But perhaps this is a little bug?