Sometimes, when I want to display a PDF files in 1Browser, I get de PDF displayed as a text file.
E.g. starting with the characters "%PDF-1.4" . I don't get it al the time so I guess it depends on how the PDF file has been generated.
These PDF files can be displayed correctly in Safari though.
1Password Version: 6.5.4
Extension Version: Not Provided
OS Version: iOS 10.3.1
Sync Type: iCloud