We have looked into your issue in details and checked your shared PDF file and the output EMF file inside the pptx file. Well, there are three fonts used in the source xlsx: Arial Regular, Calibri Regular, Calibri Bold. In the PDF file, only Calibri Regular, Calibri Bold fonts are used, but in the EMF file, only Arial Regular, Calibri Regular fonts are used, the missing of Calibri Bold font caused the text overlapping issue. Also, it seems that the PDF file and the EMF file were not generated in the same environment.
Please make sure Arial Regular(arial.ttf), Calibri Regular(calibri.ttf), Calibri Bold(calibrib.ttf) fonts are available on your env, and they are set to be used by Aspose.Cells (e.g. use FontConfigs.setFontFolder(string fontFolder, bool recursive)). Then use the following sample code to generate the PDF file and EMF file at the same time:
Workbook wb = new Workbook(sourcePath + "TextOverlapIssue.XLSX");
wb.save(destPath + "test_Java.pdf");
Worksheet sheet = wb.getWorksheets().get("Chart");
ImageOrPrintOptions imageOptions = new ImageOrPrintOptions();
SheetRender sheetRender = new SheetRender(sheet, imageOptions);
sheetRender.toImage(0, destPath + "test_Java.emf");
If the issue still exists, please share us the generated PDF file and EMF file, we will check it soon.