LibreOffice dialogs are garbled

[Sven N.]

Behaviour: The LibreOffice dialogs are completely unreadable, thus rendering the software useless.
Expected: Normal display of the dialogs.

See attached screenshot.

Kubuntu 20.04 + Wayland
Libreoffice:
Version: 6.4.5.2
Build ID: 1:6.4.5-0ubuntu0.20.04.1
CPU threads: 12; OS: Linux 5.4; UI render: default; VCL: kf5;
Locale: en-US (en_DE.UTF-8); UI-Language: en-US
Calc: threaded

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: libreoffice 1:6.4.5-0ubuntu0.20.04.1
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.8
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: KDE
Date: Fri Aug 28 11:43:18 2020
InstallationDate: Installed on 2019-09-20 (342 days ago)
InstallationMedia: Kubuntu 19.10 "Eoan Ermine" - Alpha amd64 (20190919)
SourcePackage: libreoffice
UpgradeStatus: No upgrade log present (probably fresh install)

[lotuspsychje (lotuspsychje)]

Thank you for filing this bug and make ubuntu better!
Could you please attach your dmesg log and perhaps also sudo lshw -C video ?

does your bug occur on Xorg aswell?

[Sven N. (sq-sen)]

It happens on Wayland only. Xorg works.
dmesg is attached.

[Sven N. (sq-sen)]

And here's lshw