When running using qt (i.e default Plasma install), after having selected style templates for text a few times, the typing cursor vanishes.
Temporary workaround each time it happens: Click anything in the menu, then click back in text.
Full workaround: install libreoffice-gtk3 and libreoffice-x11, then uninstall libreoffice-kf5. (corrected info)
You will loose some qt integration, but for me it is definately worth it.
Problem is upstream, but they neglect to fix it.
Alternate workaround: Upcoming 7.3 do not show this problem, but we will not package it until it is finished. You may install the beta version from upstream, but it will not have full desktop integration and filetype association by default. Use their rpm packages (compressed archives) - first uninstall Mageia LibreOffice packages.
Tracked in our Mageia Bug 29647 - loss of cursor/prompt LibreOffice Writer