Night mode in KDE Plasma flickers after upgrading Kubuntu from Groovy to Hirsute Hippo

[Saija]

I upgraded my Kubuntu machine today from Groovy to Hirsute Hippo, then I installed KDE plasma latest version from Kubuntu backports PPA. In my m>

STEPS TO REPRODUCE
1. Logon in my account with the night mode setup previously described
2. Work normally in my Plasma session
3. The night mode turns on, but every 7 seconds it's turned off

OBSERVED RESULT
The night mode turns on, but every 7 seconds it's turned off just to be turned on again

EXPECTED RESULT
The night mode should stay turned on

SOFTWARE/OS VERSIONS
Windows:
macOS:
Linux/KDE Plasma: Kubuntu Hirsute Hippo
(available in About System)
KDE Plasma Version: 5.22.2
KDE Frameworks Version: 5.83.0
Qt Version: 5.15.2

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1934216/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Chris Guiver (guiverc)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

From the details you provided, you are are NOT using Kubuntu packages, as the plasma provided with Kubuntu 21.04 is KDE Plasma 5.21 (not 5.22.2), and KDE Frameworks 5.80 (not 5.83) so it sounds like you're using 3rd party packages and not Kubuntu provided packages.

FYI: If you read the Kubuntu backports instructions, you'll note

---
Issues with Plasma itself can be reported on the KDE bugtracker [1]. In the case of packaging or other issues, please provide feedback on our mailing list [2], IRC [3], and/or file a bug against our PPA packages [4].

1. KDE bugtracker: https://bugs.kde.org
2. Kubuntu-devel mailing list: https://lists.ubuntu.com/mailman/listinfo/kubuntu-devel
3. Kubuntu IRC channels: #kubuntu & #kubuntu-devel on irc.libera.chat
4. Kubuntu ppa bugs: https://bugs.launchpad.net/kubuntu-ppa
---

So if you're using the backports PPA, then THANK YOU for helping to test KDE/Kubuntu's future products.

If you need help, you can use the IRC channels provided. I've assumed you are using the backports PPA, and thus changed the package to suit that.

[Chris Guiver (guiverc)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command only once, as it will automatically gather debugging information, in a terminal:

apport-collect 1934216

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.