We're creating a Java version of our Excel template tool by converting VB.NET code into Java. So we're using Aspose.Cells for Java and we're getting different outputs. I believe the culprit is the DeleteRows() method because there were a few bugs fixed for the .NET version in the past. I'm attaching the outputs so you can see how the Java output is stripping the header.
If this is too little information to go with, I'd be happy to attach my VB.NET project. I can't send you the Java project because it's dynamically created by our code converter.