@Ano
By testing with the latest version v24.1, we can obtain the correct HTML results. Please refer to the attachment. result.zip (12.4 KB)
The sample code as follows:
Workbook workbook = new Workbook(filePath+"test.json");
HtmlSaveOptions saveOptions = new HtmlSaveOptions(SaveFormat.HTML);
saveOptions.setExportGridLines(true);
saveOptions.setExportHeadings(true);
saveOptions.setPageTitle("Convert JSON to HTML");
workbook.save(filePath + "out_java.html", saveOptions);
If you have any questions or confusion, please provide screenshots and highlight the incorrect areas, which will be helpful for us to locate the issue.