Can't drain a node with kubectl or RancherAPI (v2.4.5)

Version: v2.4.5
cluster_type: Amazon EC2

・When try to dain a worker node with Rancher API from Rancher UI, the drain fails and entire cluster becomes unavilable.
・When try to drain a worker node with kubectl, the status of the node remains as cordon although output " drained".

Please tell me if you know how to solve this problem.