JSCH to connect to remote server to download files is giving error failed to send channel request - spring-boot

Question

I am using jsch to download filed from a remote server to local server. Below is the code segment to download the files:
Channel channel = session.openChannel("sftp");
channel.connect(channelTimeout);
channelSftp.connect(10000);
channelSftp.cd(remoteDir);
for (Object entry : channelSftp.ls(remoteDir)) {
if (entry instanceof ChannelSftp.LsEntry) {
String filename = ((ChannelSftp.LsEntry) entry).getFilename();
if (!filename.equals(".") && !filename.equals("..")) {
channelSftp.get(filename, localDir + filename);
}
}
}
but each time I run the code i am getting the below error:
20:44:09.205 [main] ERROR - Error download file
com.jcraft.jsch.JSchException: failed to send channel request
at com.jcraft.jsch.Request.write(Request.java:65)
at com.jcraft.jsch.RequestSftp.request(RequestSftp.java:47)
at com.jcraft.jsch.ChannelSftp.start(ChannelSftp.java:237)
at com.jcraft.jsch.Channel.connect(Channel.java:152)
The weird part is if I run the application in debug mode, I am not getting any error and the application completes successfully.
Can anyone help why this error is occurring only while running and not while debugging.
note - I am using spring boot application.