Discover starts up with other window's contents displayed

[Lorenzo Castoldi]

When I start Discover to install updates, the window appears to be a "copy" of another window I have open. For instance, if I'm reading Wikipedia in an open Firefox window, Discover's window will show whatever article I have open at the moment. After a few seconds, this is replaced by the spinning "loading" icon, and after this point Discover works as normal.

It's not just Firefox; I've had it copy other applications, as well as my desktop background. However, opening Discover for a second time does not cause this issue. I'm not sure if the rule is that it happens the first time each login, or only when there are new updates pending. I can drag the window around as normal while it's in this state. I'm not sure what happens if I resize it.

I would expect the buffer to be initialized (to, say, the spinning "loading" icon) before display. The bug is particularly noticeable because it sticks around for several seconds, but even one frame would be jarring and unexpected.

I don't have any similar issues with my other applications on this machine, which has an Nvidia GPU (proprietary drivers). I don't have this particular issue on my laptop, which has Intel integrated graphics.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: plasma-discover 5.18.4.1-0ubuntu1
ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30
Uname: Linux 5.4.0-29-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: KDE
Date: Fri May 15 15:45:01 2020
InstallationDate: Installed on 2019-12-30 (136 days ago)
InstallationMedia: Kubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
ProcEnviron:
 TERM=xterm-kitty
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/zsh
SourcePackage: plasma-discover
UpgradeStatus: Upgraded to focal on 2020-04-25 (19 days ago)

[Scarlett Gately Moore (scarlettmoore)]

This bug is very old, if this is still an issue please update bug with info on a supported release.