Jenkins agent not able to clone git repo, seems there is and issue with JNLP4-Connect:

Cloning the remote Git repository
ERROR: Checkout failed
Also: hudson.remoting.Channel$CallSiteStackTrace: Remote call to JNLP4-connect connection from 172.xx.3.xx/172.xx.3.xxx:38596
at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1784)
at hudson.remoting.UserRequest$ExceptionResponse.retrieve(UserRequest.java:356)
at hudson.remoting.Channel.call(Channel.java:1000)
at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler.execute(RemoteGitImpl.java:153)

From the agent logs, the slave agent are able to connect with the master, but it's suddenly terminated:

Jun 18, 2024 10:24:54 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Connected
Jun 18, 2024 10:24:59 AM org.csanchez.jenkins.plugins.kubernetes.KubernetesSlave$SlaveDisconnector call
INFO: Disabled agent engine reconnects.
Jun 18, 2024 10:24:59 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Terminated
Jun 18, 2024 10:24:59 AM hudson.remoting.Request$2 run
INFO: Failed to send back a reply to the request UserRequest:hudson.Launcher$RemoteLauncher$KillTask@1915f08c: hudson.remoting.ChannelClosedException: Channel "hudson.remoting.Channel@345786ef:JNLP4-connect connection to jenkins-iac-agent.jenkins-iac.svc.cluster.local/10.xx.71.xxx:50000": channel is already closed
Exception in thread "Thread-24" java.lang.NoClassDefFoundError: org/eclipse/jgit/internal/JGitText
at org.eclipse.jgit.internal.util.ShutdownHook.cleanup(ShutdownHook.java:85)
at java.base/java.lang.Thread.run(Unknown Source)