Thanks for your query.
We have tried to reproduce this issue using latest version Aspose.Cells for Java 18.10.1, but could not observe any issue. You may please give it a try using latest version and provide your feedback.
Output of the program using latest version is attached here for your reference:
output.zip (534.0 KB)
You can download the latest version here:
Aspose.Cells for Java v18.10.1.zip