Kubernetes-master blocked

Hello,

we have k8s cluster installed with juju:

$ juju status
Model    Controller      Cloud/Region         Version  SLA          Timestamp
default  my-controller   localhost/localhost  2.9.32   unsupported  15:40:19Z

App                    Version   Status   Scale  Charm                  Channel   Rev  Exposed  Message
containerd             go1.13.8  active       5  containerd             stable    178  no       Container runtime available
easyrsa                3.0.1     active       1  easyrsa                stable    420  no       Certificate Authority connected.
etcd                   3.4.5     active       3  etcd                   stable    634  no       Healthy with 3 known peers
flannel                0.11.0    active       5  flannel                stable    597  no       Flannel subnet 10.1.10.1/24
kubeapi-load-balancer  1.18.0    active       1  kubeapi-load-balancer  stable    844  yes      Loadbalancer ready.
kubernetes-master      1.22.13   blocked      2  kubernetes-master      stable   1078  no       Stopped services: kube-controller-manager
kubernetes-worker      1.22.13   active       3  kubernetes-worker      stable    816  yes      Kubernetes worker running.

And I am not sure why the kubernetes-master has been blocked. The log says:

Aug 30 15:15:27 my-vm-1 kube-controller-manager.daemon[21627]: I0830 15:15:27.263184   21627 dynamic_serving_content.go:110] "Loaded a new cert/key pair" name="serving-cert::/root/cdk/server.crt::/root/cdk/server.key"
Aug 30 15:15:27 my-vm-1 kube-controller-manager.daemon[21627]: unable to load configmap based request-header-client-ca-file: Unauthorized
Aug 30 15:15:27 my-vm-1 systemd[1]: snap.kube-controller-manager.daemon.service: Main process exited, code=exited, status=1/FAILURE
Aug 30 15:15:27 my-vm-1 systemd[1]: snap.kube-controller-manager.daemon.service: Failed with result 'exit-code'.
Aug 30 15:15:37 my-vm-1 systemd[1]: snap.kube-controller-manager.daemon.service: Scheduled restart job, restart counter is at 28.
Aug 30 15:15:37 my-vm-1 systemd[1]: Stopped Service for snap application kube-controller-manager.daemon.
Aug 30 15:15:37 my-vm-1 systemd[1]: Started Service for snap application kube-controller-manager.daemon.
Aug 30 15:15:37 my-vm-1 kube-controller-manager.daemon[21712]: I0830 15:15:37.987728   21712 feature_gate.go:245] feature gates: &{map[RotateKubeletServerCertificate:true]}

Any hint how can I fix it ?