Support have had this running and so far report no issues running on a DSCS9 and have suggested that this could be related to your device and not the Player itself. You also suggest that this happens with just some of your Players but not all? Could you therefore look into the differences between your hardware devices to see if this provides any clues as to why some players have this issue and others don’t. For example; Android versions running, webview/browser versions running on each device? (You can schedule the whatsmybrowser webpage into a Layout to see the details about the browser/webview version being used to render it).
A possible solution/workaround would be to convert the PDF to an image instead, and use the image widget to display it? Do let us know if the issue still persists if you do try this suggestion.