I’m using LibreOffice ver.220.127.116.11 (x64) and I’m not aware of changing a thing, but…
I performed a paste from the clipboard on a 135-page list of recipes in Writer, and suddenly the page count started rolling and a line, as if an upper border - but not, was inserted above each and every line of text, not just each paragraph. Of course, an attempt to paste in an example does not carry the lines.
The lines appear both with non-printing characters showing and without.
Anyone have an answer?