The upstream bug was marked as invalid, because LibreOffice 6.0 (default in Ubuntu 18.04) seems out of support. A similar bug appears in LibreOffice 6.4: https://bugs.documentfoundation.org/show_bug.cgi?id=132653
The upstream bug was marked as invalid, because LibreOffice 6.0 (default in Ubuntu 18.04) seems out of support. /bugs.documentf oundation. org/show_ bug.cgi? id=132653
A similar bug appears in LibreOffice 6.4: https:/