me if i was Tails, or “The Amnesic Incognito Live System”, a security-focused Debian-based Linux distribution aimed at preserving privacy and anonymity against surveillance, which connects to the Internet exclusively through the anonymity network Tor and is designed to be booted as a live DVD or live USB and never writes to the hard drive or SSD, leaving no digital footprint on the machine unless explicitly told to do so.
I had the same problem. It’s been a while but I’m fairly certain the problem can be solved by installed the appropriate integration package. Try installing these packages,
libreoffice-plasmalibreoffice-qt5libreoffice-style-breeze. Take a look at this forum thread for more info, https://discuss.kde.org/t/libreoffice-does-not-honour-kde-theme/3347