Stretched aspect ratio when viewing PDFs generated from a certain app

[CareAndRepair]

Reporting a visual issue with version 20 when used with the app PDFDocScan:
https://github.com/LittleTrickster/PDF-Doc-Scan

Previously in GOS PDF Viewer version 19, PDFs could not be opened at all from PDFDocScan due to a "invalid MIME type" related error.
(related:
LittleTrickster/PDF-Doc-Scan#16
#387 )

Now in GOS PDF Viewer version 20, I can view PDFs generated from PDFDocScan, but the aspect ratio is significantly warped / stretched.

The PDFs also display this behavior if they are saved to internal storage and opened in GOS via the file picker, without going through the PDFDocScan app.

The same PDFs will open up just fine in other PDF viewers on other systems.