I import a PDF, sign it and try to save it or share it as PDF but the resulting file is only my signature on a blank background. On a note 20 ultra with the latest updates.
@Sindri: Are you using the Samsung Notes app to edit your PDF document? If so, open Samsung Notes > Tap the 3 lines in the top left > Tap the cog in the top right of the pop up window > About Samsung Notes, and check here for any available updates that might address your current issue. In the meantime, please can you confirm if you have followed the steps laid out in the link below?
I have the same problem with Samsung Note 20 Ultra 5G.
Both Samsung Notes and Adobe Acrobat for Samsung are up to date. Worked fine with PowerPoint and image file, problems with Word document as the pages were doubled.
I've started seeing this issue on Tab S8 when annotating on pdf reader inside Samsung Notes. Note that if you don't have a default application to open PDFs, android dialog pops up showing you options to select which application you want to open the PDF with. Here you would be presented with "Samsung Notes pdf reader" and "Samsung Notes". Both belong to the same application. The difference is that with the former, the annotated pdf is saved with its changes whereever it was opened from whereas the latter saved it inside the Samsung notes app explicitly. The bug seems to cropping up when using the Samsung Notes pdf reader option and saving it as is. It only preserves the annotations made on the pdf and ignores the PDF content itself leading for the pdf saved to be blank. Samsung still hasn't fixed this issue in 2022. The issue likely is how it is dealing with layers on the pdf. Only the foreground layer with the annotations is saved whereas the background layer with original pdf content is ignored. This doesn't seem to be occurring for all pdfs so may be the pdf itself has a role in triggering this too. Samsung needs to investigate this promptly since students who spend a lot of time taking notes will see their work go to waste.