Desktop icon for pulseeffects is not displayed correctly.

The desktop icon for PulseEffect (presumably the file /usr/share/icons/hicolor/scalable/apps/pulseeffects.svg) is not displayed correctly on the KDE plasma desktop.

The shadowing(?) of the 3 lines is absent and instead the bottom right-hand corner background of the icon "space" is black.

This was also the case in Hirsute. Groovy was OK (if I remember correctly - it certainly has been OK in the past).

Picture of the problem is attached.

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: plasma-desktop 4:5.22.5-0ubuntu1
ProcVersionSignature: Ubuntu 5.13.0-21.21-generic 5.13.18
Uname: Linux 5.13.0-21-generic x86_64
ApportVersion: 2.20.11-0ubuntu71
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: KDE
Date: Tue Nov 16 17:28:59 2021
InstallationDate: Installed on 2020-05-03 (562 days ago)
InstallationMedia: Kubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
SourcePackage: plasma-desktop
UpgradeStatus: Upgraded to impish on 2021-11-11 (5 days ago)