Rancher returns failed to verify certificate: x509: certificate signed by unknown authority

[bholexy]

I added a remote cluster to ArgoCD but argoCD keeps giving me this error
Get "https://rancher.xxxxxxx.com/k8s/clusters/c-m-yyyy/version?timeout=32s": tls: failed to verify certificate: x509: certificate signed by unknown authority

I added ArgoCD cert to argocd-server-tls and argocd-repo-server-tls and also uploaded the the rancher certificate to Argocd TLS certificate upload UI