Certificate rotation problems

Similar to this post, I’m having problems connecting to a rancher managed cluster. Kubectl is complaining with:

Unable to connect to the server: x509: certificate has expired or is not yet valid: current time 2021-06-17T13:47:42+01:00 is after 2021-06-13T10:25:40Z

I’ve rotated the certificates for the cluster where rancher is running using rke cert rotate and I’ve rotated the certs for the cluster I’m trying to access through the racher ui, but I still get that error.

The cluster seems OK, and in the Rancher UI the cluster manager is working fine, but the new cluster explorer now seems dead with the page showing:

HTTP Error 500:
from /k8s/clusters/c-7xtkg/v1/schemas

What might I have missed?