gnome night light works on only one monitor

[Bickhaus]

I am running Ubuntu 19.04 with an AMD RX570, using the open source driver, and I have two Dell U2415 monitors connected via DisplayPort (not daisy-chained). Gnome Night Light only changes the color on the monitor dubbed "Monitor 1" in display settings (though the monitor I have set to primary is Monitor 2). I found a multiple posts where it was stated that using `killall gsd-color` fixed the issue. This workaround was successful for me also.

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: gnome (not installed)
ProcVersionSignature: Ubuntu 5.0.0-13.14-generic 5.0.6
Uname: Linux 5.0.0-13-generic x86_64
ApportVersion: 2.20.10-0ubuntu27
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Tue Apr 30 20:05:24 2019
InstallationDate: Installed on 2019-03-19 (42 days ago)
InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.3)
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: meta-gnome3
UpgradeStatus: Upgraded to disco on 2019-04-19 (12 days ago)