I am experiencing exactly same issue from today suddenly.
I am using Windows 10
Cryptomato 1.4.6 (Dokany)
and I can open XLS file for instance but no PDF.
Thanks for your help
After re-reading the posts, I cahnged the mounting method to webdav and I can now open the PDF files.
Don’t know much about the difference btw Dokany vs WebDav. But I confirm when switching to dokany it’s not worling