AEM JSCH auth faill issue

I am facing a issue with JSCH working fine outside the AEM. But failing inside AEM.

JSch jsch = new JSch();

// Add the private key identity
jsch.addIdentity(privateKeyPath);

// Get a session
session = jsch.getSession(username, host, port);

// Configure session properties
Properties config = new Properties();
// Important: For testing, you might set StrictHostKeyChecking to "no"
// In production, it's recommended to handle known_hosts properly.
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);

// Connect to the session
session.connect();
System.out.println("Session connected.");

This works perfectly when I run it directly with main method ( outside osgi). But gives the below error when code is ran inside AEM.

com.jcraft.jsch.JSchException: Auth fail
    at com.jcraft.jsch.Session.connect(Session.java:519)
    at com.jcraft.jsch.Session.connect(Session.java:183)

I ran the code with java 11 and AEM is also running on java 11. The code inside AEM is also able to access the private key content. ( I checked with log)

I am using the new library https://github.com/mwiede/jsch