X509 Certificate Error When Certificate isn't expired

When trying to access kubectl, I see this error

Unable to connect to the server: x509: certificate has expired or is not yet valid: current time 2021-10-03T23:20:23-04:00 is after 2021-09-29T19:21:40Z

I’ve checked the certificate in my kubeconfig file. I’ve checked the certificate for the HAProxy load balancer the web UI sits behind. Both certificates are not expired. So why am I getting this error? What other cert could be expired?

Some information about my setup:

  • Rancher v2.5.8 HA setup (single node) using k3s on Ubuntu Server 20.04
  • Rancher configured to use the domain that points to HAProxy for SSL offloading
  • Worker/Master/etcd node (single node) on Ubuntu Server 20.04