Deleting old messages (older than 300 days)

we have a problem with message reorganisation. We sat the global retention policy to 300 days for Maximum message age in channels/private groups/direct messages.
But the system keeps deleting all messages oder than 30 days…

How can we investigate deeper for the cause? I turned up logging and we see that the system deletes the messages per channel, older than a date 30 days in the past.

Are we mssing something.

Thanks in advance, regards

Server Setup Information

  • Version of Rocket.Chat Server: 2.4.9
  • Operating System: Linux (Docker Container)
  • Deployment Method: docker container in Kubernetes in open shift
  • Number of Running Instances: 2 (but doesnt matter)
  • DB Replicaset Oplog: Yes
  • NodeJS Version: v8.17.0 (from official Docker Image)
  • MongoDB Version: 4.2.5