It seems I've been able to fix the blank/white page issue. muPDF was set for unlimited memory allocation(FZ_STORE) and this caused some issues with larger documents. I've changed FZ_STORE to 16MB and it seems to play nicely now. All of the PDFs that gave me this issue seem to be fine now.

Attached is the tns for the patched version. I've also submitted a pull request on the GitHub for the project.

Please let me know if this works for you! Thanks 

nPDFv0.5b