Worker node is giving cert issue on every kubectl command

Unable to connect to the server: x509: certificate signed by unknown authority (possibly because of "crypto/rsa: verification error" while trying to verify candidate authority certificate "kubernetes")

1. Reset the node

kubeadm reset

2. Delete the config file

rm -rf $HOME/.kube/config

3. Re-join the node

# Run this on Master
kubeadm token create --print-join-command
# Copy the output of the above command on worker node

#To See current tokens and sha:
kubeadm token list
openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt  | openssl rsa -pubin -outform der 2>  /dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'