Waiting for cluster agent to connect


I have updated Rancher version to 2.2.7 and Kubernetes version to 1.14.5.
From the UI, the cluster is showing active. But we are experiencing an intermittent issue which shows,

Get waiting for cluster agent to connect

And when displaying pods or namespaces, I’m getting:

Error from server (ServiceUnavailable): the server is currently unable to handle the request (get namespaces)

Can someone pls help me?

Thank you.