Can you take a screenshot, upload it somewhere (e.g., Dropbox or Google Drive), and provide a link here? And also either link to the PDF or email it to support@zotero.org with a link to this thread?
(This is assuming you're talking about how the PDF itself is displayed. If you're talking about extracted text in annotations, that would just have to do with whatever OCR software was run on the PDF and wouldn't have anything to do with Zotero.)
(This is assuming you're talking about how the PDF itself is displayed. If you're talking about extracted text in annotations, that would just have to do with whatever OCR software was run on the PDF and wouldn't have anything to do with Zotero.)