Issue in combining PDF files using open source Java library

Hello Everyone,

Sorry, if I am asking the same question that someone has already asked/answered but am not able to find it. Here is the background of the issue: We have the individual PDF files generated from InDesign and are using Apache's PDFBox (https://www.apache.org/dyn/closer.lua/pdfbox/3.0.0-alpha3/pdfbox-app-3.0.0-alpha3.jar) to merge all the PDF files into one. All are fine except the display of the page numbers in Acrobat Reader. The first chapter (that has Arabic number 1) is taking the number from the previous file (in this case, Fronmatter Roman number). Please see the screenshot below. We are aware that creating the book PDF using InDesign's book is fine but we are not using InDesign. This is not related to Acrobat softwate and we are not looking for a Acrobat solution but are looking for a solution that the open source Java library (similar to PDFBox) can handle this (OR) if something can be done in the InDesign before creating the individual PDF so that PDFBox/any other open source Java library will produce the correct output.

The sample files are attached just in case. Any advise on this would be greatly appreciated.