I own a Note 2 and Nova Pro (with the latest firmware for both as of 1/4/19), and have a strange problem syncing pdfs between them.
I use dropbox and drop sync to synchronize my files from my Nova Pro to my computers (a Mac and PC). Everything here works fine, for the most part. Any comments (underlining, highlighting, etc.) I make to my pdfs on my Nova Pro are saved to the pdfs and readable in applications I use on my computers (Preview for Mac, Adobe for my iPhone and PC). (The only unexpected thing here is that Nova Pro won’t see comments made on my other devices as comments, but as integrated into the pdf; and any alterations to Nova Pro comments from these devices–e.g. deletions) are not synced back to the Nova Pro).
The problem: I also sync my Note 2 to these files, via dropsync. The Note 2 cannot read any comments (by which I mean, again, underlining, highlighting, etc.) that have been made on the Nova Pro. I know that these comments are part of the file, because they will show up on any other device. The Note 2 can’t decipher them.