I have the problem with LibreOffice 220.127.116.11-2/KDE5/Fedora 31 KDE Desktop/Spins upon this matter, TDF#127642.
I tried by installing Fedora 31 GNOME Desktop which LibreOffice 18.104.22.168.0+ is bundled with gtk3. And the problem , TDF#127642 has gone.
Why LibreOffice has various VCL’s ?
KDE5 looks so good, but I have to say goodbye: