By default I have the same issue using KDE and a dark theme, what I do is set a specific theme inside LibreOffice. Another thing you can look for is setting another GTK theme or color scheme inside Customization on Plasma Settings
Use another theme, look for them in Tools->Preferences
By default I have the same issue using KDE and a dark theme, what I do is set a specific theme inside LibreOffice. Another thing you can look for is setting another GTK theme or color scheme inside Customization on Plasma Settings