PDF content disappearing

I scan all my papers with a scansnap and store them in Devonthink. Recently, I looked up 34 pages paper in Devonthink, a quite important paper, and scroll through to the page I needed. Suddenly the content disappeared. I close the document, opened it again, scroll down, and found the content that had appeared again. I scrolled a little bit further to see the rest of the paper, and as I scrolled

back to the page in question, the content had disappeared again. Blank page. I searched for a word that should be on the page and DEVONthink apparently found the word on the text layer of the PDF and marked it with a yellow square on the blank page. A little bit later I searched again, and this time the word didn’t turn up at all.
I open the Time Machine and went a few months back to the document and open it with quick look. I scrolled through the document and was relieved that the content was there. From the end of the document, I scrolled back to the page question, a blank page.
The screenshot shows how half of the contact on a page is gone. A few seconds later, the rest was gone too.
What on earth is going on here? Never experience this problem before.
I would love to hear your opinions and solutions. Thanks! Per

This sounds like a display issue but this doesn’t affect or change the contents of the document. Is Preview.app able to show all pages? Which version of macOS do you use?