redshift keeps switching colours after update to 1.12-4

[AO]

Since redshift got updated to version 1.12-4 on Ubuntu Hirsute on Dec. 12th, it keeps switching between two colours, possibly brightness too, making it unusable.
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ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu55
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: Unity:Unity7:ubuntu
DistroRelease: Ubuntu 21.04
InstallationDate: Installed on 2020-03-15 (275 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Alpha amd64 (20200106)
Package: redshift 1.12-4
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 5.8.0-29.31-generic 5.8.14
Tags: hirsute third-party-packages
Uname: Linux 5.8.0-29-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lp lpadmin lxd plugdev sambashare sudo vboxusers
_MarkForUpload: True
modified.conffile..etc.default.apport: [modified]
mtime.conffile..etc.default.apport: 2020-03-15T11:56:34.801446

[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 1908195

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.

Note: if you're using GNOME & have Night Shift enabled, they can interfere with each other in my experience. No desktop etc. details have been currently provided.

[AO (aofrl10n)]

apport information

[AO (aofrl10n)]

apport information

[AO (aofrl10n)]

apport information

[AO (aofrl10n)]

FYI. This Ubuntu Hirsute is using the Unity desktop.

It turns out that after updating redshift to version 1.12-4, two redshift instances were running on the system. Only one of the two redshift-gtk could be closed (I then disabled the Redshift present in the Startup Apps), the second instance just refuses to close. Even when issuing 'killall redshift-gtk' and 'killall redshift', Redshift is still enabled and appear on the indicator bar.
After issuing several such killall command, the screen turns darker and more red after each killall.
Checking the system monitor, two redshift processes and one redshift-gtk are running. Killing the three processes doesn’t return the screen to its normal display and the three processes restart by themselves, the screen turning yet darker and more red, to the point of becoming unreadable. I had to reboot the system.
Upon restarting, two redshift processes and one redshift-gtk are running (that can’t be killed as explained above).

[AO (aofrl10n)]

A colleague of mine upgraded his Ubuntu 20.10 Groovy to Ubuntu 21.04 Hirsute, and though Redshift-gtk worked perfectly before the upgrade to Ubuntu 21.04, he experienced the same issues after the upgrade.
It seems to be related to the interaction of Redshift-gtk with Ubuntu Hirsute.

This bug report has seen no resolution activity for over 50 days.

Assistance would be appreciated.