Slave agent can't be created after initial deployment of Jenkins

[xscript]

After the initial setup of Jenkins, slave agent can't be created by Kubernetes plugin. Below is the error message from Jenkins.

Connection #84 failed
java.io.EOFException
	at java.io.DataInputStream.readFully(DataInputStream.java:197)
	at java.io.DataInputStream.readFully(DataInputStream.java:169)
	at hudson.TcpSlaveAgentListener$ConnectionHandler.run(TcpSlaveAgentListener.java:216)

Work around is going to Manage Jenkins -> Configure System page and clicking "Save" button. Then slave agent can be created successfully afterwards.
Meanwhile, below is the error message when saving the configuration page.

Father of PodEnvVar [getValue()=36, getKey()=GROUP_SUFFIX] and its getDescriptor() points to two different instances. Probably malplaced @Extension. See http://hudson.361315.n4.nabble.com/Help-Hint-needed-Post-build-action-doesn-t-stay-activated-td2308833.html

Initial suspect is this is a bug from Jenkins Kubernetes Plugin.

[ArchangelSDY]

As I'm not very familiar with the initialization process of this Jenkins instance, if you believe this is a bug from Jenkins Kubernetes Plugin you can file an issue directly at Jenkins Jira and explain the details about how you use it.

You can also try Azure Container Agents Plugin as an alternative.