After upgrading Rancher from 2.4.x to 2.6.6, k8s version is not updated on 2 worker nodes

I have updated Single node Rancher cluster from 2.4.x to 2.6.6 using docker commands. Upgrade was successful and my existing nodes are all available and workloads are also available.
From 34 nodes, 2 nodes are still running K8S version 1.18.x where as I have selected 1.22.x.

Can someone please help what is wrong with these 2 nodes? How can I update K8S version on these nodes ?