JGit RefNotFoundException When Checking Out Branch from Azure DevOps Repository while trying to access the branch

I'm using JGit to clone and interact with a Git repository hosted on Azure DevOps. My goal is to clone the master branch, checkout to my specified branch (branchName), update the <revision> value from the pom.xml file under the <properties> tag (using pomManipulations.modifyPomFile(pomFilePath)), and then push the updated local branch back to the remote repository of the same branch. While the revision value is fetched correctly, I'm encountering a RefNotFoundException when attempting to check out the branch.

Issue: The code successfully clones the repository and fetches the revision value from pom.xml, but when attempting to checkout the master branch, I receive a RefNotFoundException. This suggests that the branch reference cannot be resolved.

NOTE: The branch name I'm providing is correct and that branch also exists remotely in AzureDevops.

Here's the relevant portion of my code:

import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.transport.UsernamePasswordCredentialsProvider;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

public class AzureDevOpsBranchUpdater {

    private static final String PAT_FILE_PATH = "path/to/pat.txt"; // Update with the correct path

    public String updatePom(String organization, String project, String repositoryName, String branchName, String Id) {

        String repoUrl = "https://dev.azure.com/" + organization + "/" + project + "/_git/" + repositoryName;
        String localRepoPath = "C:/Users/" + Id + "/AutomatePipeline/" + repositoryName;
        String pomFilePath = localRepoPath + "/pom.xml";

        try {
            // Read the Personal Access Token (PAT)
            String PAT = Files.readString(Paths.get(PAT_FILE_PATH)).trim();

            // Clone the repository and checkout master
            Git git = Git.cloneRepository()
                    .setURI(repoUrl)
                    .setDirectory(new File(localRepoPath))
                    .setCredentialsProvider(new UsernamePasswordCredentialsProvider("", PAT))
                    .setBranch("master")
                    .call();

            // Checkout the specified branch
            git.checkout().setName(branchName).call();

            // Pull the latest changes from master
            git.fetch().setCredentialsProvider(new UsernamePasswordCredentialsProvider("", PAT)).call();

            MergeResult mergeResult = git.merge()
                    .include(git.getRepository().findRef("master"))
                    .call();

            if (!mergeResult.getMergeStatus().isSuccessful()) {
                return "Merge conflicts occurred: " + mergeResult.getMergeStatus();
            }

            // Modify the pom.xml file
            pomManipulations.modifyPomFile(pomFilePath);

            // Commit the changes
            git.add().addFilepattern("pom.xml").call();
            git.commit().setMessage("Updated pom.xml").call();

            // Push the changes to the remote branch
            git.push().setCredentialsProvider(new UsernamePasswordCredentialsProvider("", PAT)).call();

            return "Branch "+ BRANCH +"'s pom.xml updated successfully";

        } catch (GitAPIException | IOException e) {
            e.printStackTrace();
            return "Error: " + e.getMessage();
        }
    }

    private String getRevisionFromPom(String pomFilePath) throws IOException {
        XmlMapper xmlMapper = new XmlMapper();
        JsonNode root = xmlMapper.readTree(new File(pomFilePath));
        JsonNode propertiesNode = root.findPath("properties");
        if (propertiesNode.isMissingNode()) {
            return null; // <properties> tag not found
        }
        JsonNode revisionNode = propertiesNode.findPath("revision");
        if (revisionNode.isMissingNode()) {
            return null; // <revision> tag not found in the <properties> section
        }
        return revisionNode.asText(); // Return the revision value
    }
}

Troubleshooting Steps Taken:

• Verified the branch name and existence in the remote repository.
• Ensured the Personal Access Token (PAT) has necessary permissions. Checked network connectivity and repository URL.
• Confirmed Git configurations are correct.

Question: What could be causing the RefNotFoundException during the checkout process, and how can I resolve it?