Paginated Report Matrix with Dynamic Columns Causing PDF Export Issues

Hi NB8​,
Thanks for the update. I would recommend checking the following areas based on Microsoft's guidance for paginated reports:

•    For a dynamic matrix, the Product Type column group can expand horizontally and the PDF renderer can paginate the matrix across multiple pages. Consider using landscape orientation, appropriate margins/column widths, and repeating row headers across horizontal pages for readability.

•    For the unexpected blank pages, first verify that the report body width doesn't exceed the available page width:
Report body width <= Page width - (Left margin + Right margin)

•    Also check for excess whitespace below the report body, unnecessary page breaks on the matrix/groups, and the ConsumeContainerWhitespace property.

•    Use Print Preview to determine how the report is being split into physical pages before exporting to PDF.

For more details, please refer to the below Official Microsoft documentation:
Avoid blank pages when printing paginated reports - Power BI | Microsoft Learn

Rendering Behaviors in a Power BI Paginated Report - Power BI | Microsoft Learn

Control row & column headings in a paginated report - Microsoft Report Builder & Power BI Report Builder | Microsoft Learn

I hope this helps. Please feel free to reach out if you have any further questions.
Thank you.