Dynamic Panel within Dynamic Panel: The inner Dynamic Panel doesn't display the specified initial number of panels

[JaneSjs]

Usage Scenario: a Panel Dynamic is placed inside another Panel Dynamic question.
View Demo

{
 "logoPosition": "right",
 "pages": [
  {
   "name": "page1",
   "elements": [
    {
     "type": "paneldynamic",
     "name": "question1",
     "templateElements": [
      {
       "type": "expression",
       "name": "question2",
       "expression": "{panelIndex}"
      },
      {
       "type": "paneldynamic",
       "name": "question3",
       "templateElements": [
        {
         "type": "expression",
         "name": "question4",
         "expression": "{panelIndex}"
        }
       ],
       "panelCount": 5
      }
     ],
     "panelCount": 3
    }
   ]
  }
 ]
}

Issue: The inner Panel Dynamic question doesn't display the specified initial number of panels (5)