Daily Plan should allow non-recursive search in folders

Current Situation

When searching in Daily Plan items with the search criteria "folder" - not recursively - then the result always is empty. This applies to any search criteria as long as they are combined with a search for folders. 

Desired Behavior

When searching in the Daily Plan items with the search criteria "folder" - not recursively - then the result should contain the correct daily plan items.

The post body for the API call ./plan to reproduce the error is

{
  "jobschedulerId": "jobschedulerId",
  "dateFrom": "2020-07-27T22:00:00Z",
  "dateTo": "2020-07-28T22:00:00Z",
  "folders": [
    {
      "folder": "/aFolder",
      "recursive": false
    }
  ],
  "jobChain": "/aFolder/aJobChain"
}