Hi,
Uninstalling libreoffice-kf5 and libreoffice-qt solved the problem for me
Interesting, though the upstream commiit is so generic it probably isn't a kf5-specific bug.
Or it is a generic problem just exhibiting with KDE.
Anyways: As you use sid, you just can install the packages from experimental to have it fixed.
They wil end up in unstable next week
anywy when 7.4.2 gets released.
Regards,
Rene