DT 3.6.2 macOS 11.3-beta (20E5186d)
Procedure: 1. Drag a PDF (in my case created by ScanSnap) to Inbox. Verify that PDF file has kind = PDF Document. Verify that it can be viewed and scrolled up and down.
Use Contextual Meny, select OCR, to searchable PDF. Verify file kind changes to PDF+Text. Scroll document and the text disappears. Further, only page 1 is visible. Once the text has disappeared, DT needs to select another document, then return to the first one to get the text back. Scrolling again makes the text disappear. Exporting, using Files and Folders, and viewing with macOS Preview results in empty pages. Viewing with PDF Expert, text is shown for page 1 but not for the following pages.
I have reinstalled DT, but not ABBY, obtaining same behaviour.
Syncing the OCR-ed file to DTTG3 and here the file behaves correctly. It can be scrolled, edited and annotated.
Syncing back this file to DT, the appearance is still the same, ie a black page, but the editing done in DEVONthink To Go are in fact shown, ie highlights and underlines!
Sorry for all the text, but I need help