Preview highlighting has disappeared

Hello alliewilsonn,

Thank you for using Apple Support Communities.

We understand that you are missing some highlighting and annotations you made to a document in Preview has disappeared. You may be able to restore past versions of the PDF document that has the highlights using the steps in this resource: View and restore past versions of documents on Mac

To prevent this from occurring again, we have some steps to take to troubleshoot the issue. When you're ready, follow the steps below and let us know the result.

1. Use Preview to open a PDF which is missing some of your annotations that were added in the past.
2. Select File menu > Duplicate to create a duplicate of the PDF opened from Step 1, then edit the document's name (at the top of the window), so that it ends in "(annotations from [today's date])". Replace "today's date" with today's actual date.
3. Close the duplicate PDF, whose name ends in "(annotations from [today's date])".
4. The original copy of this PDF (which was opened in step 1) should still be open. Use File menu > Revert To > Browse All Versions to restore a past version of the document, which is not missing annotations. If you're unable to restore a version of the PDF that contains the missing annotation using File menu > Revert To > Browse All Version, then you will need to restore a previous version of the PDF from a backup.
5. If you'd like to add additional annotations or make other changes: make those changes to the PDF, close the window, reopen the PDF, and verify that previous and newly added annotations are all showing.

Let us know how this goes, and we'll proceed from there.

Best regards.

Hey there, I contacted apple about this problem and they will let me know on friday what's up. It's a well known problem on the forums. Let's see if they can fix it with a new security update. Will let you know.

It seems the apple engineers are working on it. You can expect a correction in the next 1-2 weeks, through a security update on catalina, or a normal update on big sure. Fingers crossed that it will work after that!