appsettings.json with array not being transformed correctly.

[JR33D]

I have an issue where I'm using your task to read my appsettings.{env}.json transform file as part of a yaml pipeline, I can see the settings get loaded into the variables, but then it isn't applying to the end file for arrays. Everything else seems to work as expected.
appsettings.{env}.json

  "SQS": {
    "RunWindows": [
      {
        "Start": "04:00:00",
        "End": "21:30:00",
        "TimeZone": "UTC"
      }
    ]
  },

appsettings.json

"SQS": {
  "RunWindows": [
    {
      "Start": "10:00:00",
      "End": "20:00:00",
      "TimeZone": "UTC"
    }
  ]
}

I can see the output in the pipeline is coming out as SQS.RunWindows1.Start, SQS.RunWindows1.End, SQS.RunWindows1.TimeZone
I believe this should be SQS.RunWindows.1.Start, SQS.RunWindows.1.End, sqs.runwindows.1.TimeZone based on the
JSON variable substitution notes on Microsoft's FileTransform.

Am I misunderstanding something here or has this issue just not come up?

I believe the issue is in this line of code and the fix would be just to add the period before adding the number
prfx = thisDataItem.PrefixChain + (arrayNDX + 1).toString();