I bumped Grafana to the latest version after some tweaking (had to bypass built in nginx-proxy as websockets were not working, this will probably break grafana proxying through rancher so only use if you have an ingress configured) HELM value overrides:

grafana:
  image:
    repository: "grafana/grafana"
    tag: "9.1.2"
  service:
    portName: grafana
    targetPort: 3000

Useful links to look at. The Rancher's monitoring chart uses the official Grafana chart though it mirrors it and uses an old version of the chart. https://github.com/rancher/charts/tree/dev-v2.6/charts/rancher-monitoring/100.1.3%2Bup19.0.3/charts/grafana/templates https://github.com/grafana/helm-charts/tree/main/charts/grafana