Pdf Files disappearing after iPadOS 17.2 update

The night when my iPad updated automatically at least 10 (random) pdf files, that were saved on my iPad disappeared. I could see them in recent folder, but when i opened them it was black screen. I couldnt move them, share, rename etc. altough the file had the information when it was last edited.

I contacted apple support and they couldn’t do anything about it, except suggested that in the future I save my files in iCloud drive.

So I did that, re-did all the notes for my exam (that is in a week). Today, when I was editing on my ipad, the file that I was using was not opening again (like the previous time), only this time I could share/rename/delete it, but still it was black and couldn’t open on any device.

So i started editing the file copy directly in iCloud drive and it disappeared as well… like on my iPad.

Has anyone else experiences this after the update? Did you manage to solve it???

My exam is in a week and all my notes (summary of 600 page book) are gone… help