Decrease numberInstances and editing any parameters hangs operator on Updating status

[telepenin]

I'm just trying to decrease amount of numberInstances (2 -> 1) and edit resources.limits.cpu postgresql parameters (500m -> 600m) after provisioning minimal configuration for the latest operator (v1.6.3).

How to reproduce the issue:

• install latest postgresql operator (v1.6.3 at this moment)
• using postgres-operator/manifests/minimal-postgres-manifest.yaml with additional postgresql.parameters and resources sections for the editing in the next steps

apiVersion: "acid.zalan.do/v1"
kind: postgresql
metadata:
  name: acid-minimal-cluster
  namespace: default
spec:
  teamId: "acid"
  volume:
    size: 1Gi
  numberOfInstances: 2
  users:
    zalando:  # database owner
    - superuser
    - createdb
    foo_user: []  # role for application foo
  databases:
    foo: zalando  # dbname: owner
  preparedDatabases:
    bar: {}
  postgresql:
    version: "13"
    parameters:  # Expert section
      shared_buffers: "32MB"
      max_connections: "10"
      log_statement: "all"

  resources:
    requests:
      cpu: 10m
      memory: 100Mi
    limits:
      cpu: 500m
      memory: 500Mi

• kubectl apply -f pg-manifest.yaml
• when the status cluster is Running decrease numberOfInstances -> 1 and increase resources.limits.cpu -> 500m (also I've faced this issue if I edit something in the postgresql.parameters section)
• The cluster hangs on Updating status

root@ntelepenin:~# k get pg -w
NAME                   TEAM   VERSION   PODS   VOLUME   CPU-REQUEST   MEMORY-REQUEST   AGE   STATUS
acid-minimal-cluster   acid   13        2      1Gi      10m           100Mi            0s    
acid-minimal-cluster   acid   13        2      1Gi      10m           100Mi            0s    Creating
acid-minimal-cluster   acid   13        2      1Gi      10m           100Mi            44s   Running
acid-minimal-cluster   acid   13        1      1Gi      10m           100Mi            3m    Running
acid-minimal-cluster   acid   13        1      1Gi      10m           100Mi            3m    Updating

operator log at this time - https://pastebin.com/zTHRa2YS

After 10 minutes status:

root@ntelepenin:~# k get pg -w
NAME                   TEAM   VERSION   PODS   VOLUME   CPU-REQUEST   MEMORY-REQUEST   AGE   STATUS
acid-minimal-cluster   acid   13        2      1Gi      10m           100Mi            0s    
acid-minimal-cluster   acid   13        2      1Gi      10m           100Mi            0s    Creating
acid-minimal-cluster   acid   13        2      1Gi      10m           100Mi            44s   Running
acid-minimal-cluster   acid   13        1      1Gi      10m           100Mi            3m    Running
acid-minimal-cluster   acid   13        1      1Gi      10m           100Mi            3m    Updating
acid-minimal-cluster   acid   13        1      1Gi      10m           100Mi            13m   UpdateFailed
acid-minimal-cluster   acid   13        1      1Gi      10m           100Mi            13m   Running

operator log - https://pastebin.com/TrAg9CtJ

time="2021-07-08T07:56:03Z" level=debug msg="unsubscribing from pod \"default/acid-minimal-cluster-1\" events" cluster-name=default/acid-minimal-cluster pkg=cluster worker=1
time="2021-07-08T07:56:03Z" level=error msg="could not sync statefulsets: could not recreate pods: could not recreate replica pod \"default/acid-minimal-cluster-1\": pod label wait timeout" cluster-name=default/acid-minimal-cluster pkg=cluster worker=1

Could be relevant - #1362

Which image of the operator are you using? Using the latest master's configuration
Where do you run it: cloud/kvm - minikube, cloud/kvm - k3s
Are you running Postgres Operator in production? no, but faced it on the k3s deploy
Type of issue? Bug report

[FxKu]

Does it still happen with the newest version?