I am working with LibreOffice 126.96.36.199 and Zotero 6.0.4 on macOS Catalina. I have been working on a long LO document (about 400 pages) for some time which includes a lot of Zotero citations. I sent part of the text to a proofreader (in a newly created document), who read/corrected it with LibreOffice. Now, I want to copy the corrected text of the proofread document into my old, longer document, but am unable to copy/paste the zotero citations, as they get lost (they are not preserved, the citation links are gone). This is weird, since copying them from the proofread document to another, newly created document, works. Also, copying citations out of another random LO-document to the long document always works. I can’t figure out, which document is the problem here, since only the combination of those two specific documents does not work. I want to avoid manually adding all the citations again, so what do I do?
p.s. I already consulted with the Zotero-developers, who could not figure out the problem. I therefore think it must have something to do with LibreOffice.