Viewer pane wont show PDFs - PDF Architect compatibility

I've had Dopus for over ten years with no problems, currently on 12.23 (64-bit). Recently, I changed my PDF software to PDF Architect (version 8) from a Nuance programme and I no longer have PDF viewer pane previews. Is this a basic incompatibility or does it just need a tweak? Is there a simple solution?

Does it work in File Explorer's viewer pane?

No, it doesn't. Good thought.