The reason :
apply before joining the worker nodes, the the dashboard will be on the master node. (g99k8s = master node)
kube-system kubernetes-dashboard-77fd78f978-sxr98 1/1 Running 1 2d19h 10.244.0.25 g99k8s <none>
apply after the joining of the worker nodes, due to the auto scaling, the dashboard will be scaling to the worker node.
Is that true ?