Admin API pause-all-alerts on v8.5.2

pause-all-alerts api is answering with a message “alerts un paused” and state pending.

Here is an example answer:
“alertsAffected”: 240,
“message”: “alerts un paused”,
“state”: “pending”

Documentation is not clear to what this means

grafana version?

Can you confirm: are you using the new Unified Alerting platform or the legacy platform?