Using aspose-slides-18.11-jdk16 to convert ODP to PPTX.
Converting slide with text having numbered lines. Blank lines are numbered in ODP, but not in PPTX. It could be that Powerpoint cannot number blank lines. But some of the trailing blank lines are numbered and others are not.
Code below:
Presentation presentation = new Presentation(inputPath);
presentation.save(outputPath, SaveFormat.Pptx);
Before/after sample attached
numbers.zip (46.7 KB)