Unified Alerting alert groups/group by always showing "no options found" (how to use?)

  • Grafana version? 8.3.6 and 8.4.0
  • Self Hosted Grafana OSS
  • Unified Alerting
  • No migration, import from Prometheus rules
  • Prometheus 2.33.x
  • Ubuntu 20.04, x64
  • Built-in/embedded alert manager

What are you trying to achieve?
Configure custom alert groups

How are you trying to achieve it?
Grafana UI, alert panel

What happened?
Cannot do anything, it only shows “no options found”

What did you expect to happen?
Being able to create custom groups based on labels (severity=critical, etc)

Is it not possible to setup alert groups with the built in alertmanager?
What am I missing here?