I've made a break and have tried the version of LibreOffice from Debian Backports. The check-box works fine now. But the only packages that have been upgraded are those relative to LibreOffice, none from KDE Framework 5:
fonts-opensymbol libreoffice-base-core libreoffice-calc libreoffice-common libreoffice-core libreoffice-draw libreoffice-gtk3 libreoffice-help-common libreoffice-help-en-gb libreoffice-kde5 libreoffice-l10n-en-gb libreoffice-math libreoffice-qt5 libreoffice-script-provider-python libreoffice-style-breeze libreoffice-style-colibre libreoffice-style-tango libreoffice-writer python3-uno qtgstreamer-plugins-qt5 uno-libs3 ure Doesn't it mean that the bug was there, in LibreOffice? If that's right, Will the fix be back-ported to the version of Debian Buster? Thank you.
