Where should I be looking if a previously working fine Rancher cluster starts experiencing issues like the following page being unable to be located in the rancher UI (eg having a 404 error)? https://rancher.my.url/k8s/clusters/c-mllf6/api/v1/namespaces/cattle-monitoring-sys[…]g-grafana:80/proxy/api/dashboards/uid/rancher-cluster-nodes-1