report_cb has no effect?

[ericb-summit]

With an empty config block, it doesn't seem that the report_cb callback is actually being called. For instance, I see this in the log

{
  "msg": {
    "label": "{application_controller,progress}",
    "report": "[{application,tas},{started_at,'tas@ims-tr01'}]"
  },
  "domain": "[otp,sasl]",
  "error_logger": {
    "report_cb": "fun application_controller:format_log/1",
    "tag": "info_report",
    "type": "progress"
  },
  "file": "application_controller.erl",
  "gl": "<0.1353.0>",
  "level": "info",
  "line": 2107,
  "logger_formatter": {
    "title": "PROGRESS REPORT"
  },
  "mfa": "application_controller:info_started/2",
  "node": "tas@ims-tr01",
  "pid": "<0.1326.0>",
  "report_cb": "fun application_controller:format_log/2",
  "time": 1743063955424511
}

The report_cb is supposed to format this mess into something human readable using fun application_controller:format_log/2. It just never seems to be called, looking at the code, it shoudld be . A plaintext formatter, say logger_color_formatter shows a friendly message. I would expect that friendly message to be part of the JSON output, if not as msg then as part of some other field.

Am I doing something wrong? Thanks