PDF files content goes missing while opening on Preview app on macOS Monterey

Depending on how that PDF was originally created, there may be features in it that Preview simply does not support owing to the PDF frameworks Apple is using. I always recommend that one install the current version of Adobe Acrobat Reader (not Acrobat Pro trial) and retry opening the PDF in that application. Adobe has the ability to keep the PDF handling code in Reader far more current than Apple and it may make the difference.

Apple provides a free Quick Action in the Finder named Create PDF. It allows you to select two or more PDFs in the order you want them merged by clicking on the first to select it and then using the cmd+key to click add more PDFs. Then you right-click on the first selected PDF and from the contextual menu, choose Quick Actions > Create PDF.

A new PDF is written using the base name of the first selected PDF with a 2 appended to the original basename.

Realmace wrote:

Is it just me or does the Preview app have a weird bug that destroys PDFs.

It's not you.

Not even every page but the first page of PDF files gets erased and I end up with a blank page.

Ironically enough, this wasn't the PDF-destroying Preview bug that I had in mind.

This is very frustrating as I work with a lot of PDFs so I try to merge and compress them but as soon as I open it and scroll down and scroll back up, the first page disappears immediately. And I end up with a blank first page, all the content is lost. Additionally, the 'Compress File Size' feature is a complete waste because it only takes off a few kilobytes which is absolutely useless as opposed to other PDF compressors that would not destroy your PDF and take off a lot of megabytes when it compresses your PDF. I love apple but this Preview feature is not great at all

It's right there on the tin. That's why they call it "Preview" and not "PDF Merge and Compress". You'll have to find a different tool. Unfortunately, all these freebie PDF tools have pretty much ruined the market for more powerful tools. There used to be a couple of really great ones, but they're gone now. Can't make a living as a PDF-man anymore.