When I manually enter the data, here is what shows:

When I fill the text field using the code shown below, here is what shows:

Why the difference?

Thank you for any assistance you can give.

Here are some notes that may or may not be relevant:

The template pdf is available at:
https://www.irs.gov/pub/irs-pdf/f1065sk1.pdf

Getting this warning:

WARNING: Using fallback font Helvetica for HelveticaLTStd-Roman

The IRS forms are created with Adobe LiveCycle Designer, an application that only runs on Windows and costs many thousands of dollars. As such I cannot edit the PDF with Acrobat Pro.

Here is minimal code to duplicate the problem.

package util.pdf.box;

import util.file.BytesToFile;
import util.file.FileToBytes;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDDocumentCatalog;
import org.apache.pdfbox.pdmodel.interactive.form.PDAcroForm;
import org.apache.pdfbox.pdmodel.interactive.form.PDField;

import java.io.ByteArrayOutputStream;

public class PdfFormFiller {

    public byte[] fill(
        byte[] template,
        String key,
        String value
    ) {

        byte[] pdfBytes = new byte[]{};
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try (
            PDDocument doc = PDDocument.load(template)
        ) {
            PDDocumentCatalog pdDocCatalog = doc.getDocumentCatalog( );
            PDAcroForm acroForm = pdDocCatalog.getAcroForm();
            PDField field = acroForm.getField(key);
            field.setValue(value);
            doc.save(baos);
        } catch ( Exception e ) {
            System.out.println( e.getMessage( ) );
        }
        pdfBytes = baos.toByteArray( );
        return pdfBytes;

    }

    public static void main(String[] args) {

        String filePath = "/Users/johndoe/f1065sk1.pdf";
        byte[] pdfBytes = FileToBytes.readFile( filePath );
        PdfFormFiller pdfFormFiller = new PdfFormFiller( );
        byte[] pdfFilled = pdfFormFiller.fill(
            pdfBytes,
            "topmostSubform[0].Page1[0].LeftCol[0].f1_7[0]",
            "NamenAddressnCity, State Zip"
        );
        String outDirName = "/Users/johndoe";
        String outFileName = "f1065sk1.filled.pdf";
        BytesToFile.writeToDirFile( pdfFilled, outDirName, outFileName );

    }

}