Why does group_by in the child policy not work?

[mihalt]

• What Grafana version and what operating system are you using?
  Grafana v12.3.1 (3a1c80ca7c)

• What are you trying to achieve?
  To have grouped alerts by message and service name and get just one email message by message label and one more message if service_name label is different too.

• How are you trying to achieve it?
  I tried to delete service_name, but grouping by message doesn’t appeared.

• What happened?
  I see in web interface child policies:

  
  
  But I get all messages by evaluation period in one message.

• What you expected to see?
  Grouped separate messages. And also I voted for this topic, because I can’t edit policies from web interface and it is hard to debug problems like this.

• Can you copy/paste the configuration(s) that you are having problems with?

  policies:
  - receiver: grafana-default-email
  group_by:
    - grafana_folder
    - alertname
  
  group_wait: 30s
  group_interval: 5m
  repeat_interval: 4h
  
  routes:
    - receiver: grafana-default-email
      object_matchers:
        - ["message", "=~", ".+"]
      group_by: ["service_name", "message"]
      mute_time_intervals:
        - no_night
  

• Did you receive any errors in the Grafana UI or in related logs? If so, please tell us exactly what they were.
  No

• Did you follow any online instructions? If so, what is the URL?
  I see that routes syntax is the same as parent Use configuration files to provision alerting resources | Grafana documentation