Open and save PDF

On PDF Architect 7 Free, every time I opened an attachment with Microsoft Edge and save it, automatically opened the saved file on PDF Architect 7.
Just installed PDF Architect 8 Free, and it does not open automatically after I saved a file, and could not find a any setup on option/general to change that. Can you help?
Also, even I had selected on Windows to open PDF files with PDF Architect 8, it continous opening with the browser app (Edge). Just notice the default option to open PDF files with PDF Architect on General/Option is blocked (not selected) and I am not being able to change it.