The logs will contain:

2022-06-26 03:34:30,435 WARN [org.bf2.ope.eve.ResourceEventSource] (OkHttp https://172.30.0.1/...) Secret redhat-kas-fleetshard-operator/fleetshard-observability does not have OwnerReference

Every time the secret is reconciled - on restart, modification, etc. However this is just noise and should be removed.

The simplest solution is probably to set the owner to the managed kafka agent resource.