Recently there is some changed in firewalld that creates issues with kind.
For my own shitty memory.
To run the grafana-operator I have started to use a ingress.
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/main/deploy/static/provider/kind/deploy.yaml
Update deploy/examples/Grafana.yaml to set spec.client.preferService: false
yq -i '.spec.client.preferService = false' deploy/examples/Grafana.yaml