Description of problem:

I clicked UI, cluster details page, to change the channel of the managed cluster from stable-4.19 to fast-4.20

No change on the managed cluster

Version-Release number of selected component (if applicable):

MCE 2.10 / ACM 2.15

How reproducible:

rarely!

Steps to Reproduce:

1. in cluster details page of ACM/MCE
2. have an imported cluster
3. click the Channel edit to change the channel
4. see that the Channel is updated on ACM UI, however, nothing happens at the managed cluster
5. click Upgrade Available from ACM and select a new version, nothing happens at the managed cluster

Actual results:

Managed cluster does not change channel.

Managed cluster also does not initiate OCP update.

Expected results:

I expect channel change to happen at managed cluster, when initiated from ACM UI

I expect cluster update to begin at managed cluster, when initiated from ACM UI

Additional info:

CluserCurator was deleted from the managed cluster namespace at the hub, this allows channel change and cluster update to work again.

clusterCurator looks like:
 
apiVersion: cluster.open-cluster-management.io/v1beta1
kind: ClusterCurator
metadata:
creationTimestamp: '2025-08-04T14:08:41Z'
generation: 61
managedFields:

• apiVersion: cluster.open-cluster-management.io/v1beta1
  fieldsType: FieldsV1
  fieldsV1:
  'f:status':
  .: {}
  'f:conditions': {}
  manager: curator
  operation: Update
  time: '2025-10-17T08:36:09Z'
• apiVersion: cluster.open-cluster-management.io/v1beta1
  fieldsType: FieldsV1
  fieldsV1:
  'f:spec':
  'f:curatorJob': {}
  'f:destroy':
  .: {}
  'f:jobMonitorTimeout': {}
  'f:install':
  .: {}
  'f:jobMonitorTimeout': {}
  'f:scale':
  .: {}
  'f:jobMonitorTimeout': {}
  manager: manager
  operation: Update
  time: '2025-12-11T01:49:29Z'
• apiVersion: cluster.open-cluster-management.io/v1beta1
  fieldsType: FieldsV1
  fieldsV1:
  'f:spec':
  .: {}
  'f:desiredCuration': {}
  'f:upgrade':
  .: {}
  'f:channel': {}
  'f:desiredUpdate': {}
  'f:monitorTimeout': {}
  manager: unknown
  operation: Update
  time: '2025-12-11T15:56:01Z'
  name: aro-central
  namespace: aro-central
  resourceVersion: '1352487264'
  uid: aad6bb6d-3d3f-4a7b-a95f-901d958d9aa6
  spec:
  curatorJob: curator-job-qd8lf
  desiredCuration: upgrade
  destroy:
  jobMonitorTimeout: 5
  install:
  jobMonitorTimeout: 5
  scale:
  jobMonitorTimeout: 5
  upgrade:
  channel: ''
  desiredUpdate: 4.19.17
  monitorTimeout: 120
  status:
  conditions:
• lastTransitionTime: '2025-10-17T08:36:09Z'
  message: 'curator-job-g56zb DesiredCuration: upgrade Version (4.19.6;'
  reason: Job_has_finished
  status: 'True'
  type: clustercurator-job