gnome-software continues running in the background even after its window is closed

1) Ubuntu 20.04.3 LTS
2) gnome-software 3.36.1-0ubuntu0.20.04.0
3) Closing the window should kill the process altogether
4) The process remains in the background instead

[ STEPS TO REPRODUCE ]

This becomes obvious when launched from the shell:

~ gnome-software &
[1] 7972
~ 11:25:23:0836 Gs enabled plugins: desktop-categories, fwupd, os-release, packagekit, packagekit-local, packagekit-offline, packagekit-proxy, packagekit-refine-repos, packagekit-refresh, packagekit-upgrade, packagekit-url-to-app, appstream, desktop-menu-path, hardcoded-blacklist, modalias, odrs, packagekit-refine, rewrite-resource, snap, packagekit-history, provenance, systemd-updates, generic-updates, provenance-license, icons, key-colors, key-colors-metadata
11:25:23:0836 Gs disabled plugins: dpkg, dummy, repos
11:25:26:0660 Gs Only 0 apps for recent list, hiding
11:25:31:0006 Gs automatically prevented from changing kind on system/snap/*/runtime/io.snapcraft.bare-EISPgh06mRh1vordZY9OZ34QHdd7OrdR/latest/stable from runtime to unknown!
11:25:31:0817 Gs automatically prevented from changing kind on system/snap/*/runtime/io.snapcraft.core20-DLqre5XGLbDqg9jPtiAhRRjDuPVa5X1q/latest/stable from runtime to unknown!
11:25:32:0448 Gs automatically prevented from changing kind on system/snap/*/desktop/io.snapcraft.snapd-PMrrV4ml8uWuEUDBT8dSGnKUYbevVhc4/latest/stable from desktop to unknown!
11:25:32:0721 Gs automatically prevented from changing kind on system/snap/*/runtime/io.snapcraft.core18-CSO04Jhav2yK0uz97cr0ipQRyqg0qQL6/latest/stable from runtime to unknown!

---- here, the window is closed but the process is still running as shown below ----

~ jobs
[1]+ Running gnome-software &

---- Launching Software, window appears ----
~ wmctrl -lpG | grep 'Software$'
0x02600007 0 7972 29 -8 1274 916 hp Software

---- Closing Software, window disappears, yet the process is still running as shown above ----
~ wmctrl -lpG | grep 'Software$'
~

[ WORKAROUND ]
The workaround here is to kill the process manually, e.g. `pkill gnome-software`.

[ SUGGESTION ]
Is it designed so to prevent interruptions (accidental or not) during updates? If it is, perhaps a more elegant way would be to display a confirmation dialog/prompt/popup in the case of an ongoing update process, gracefully quit the program otherwise (the process is killed for good).

====END OF REPORT====

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: gnome-software 3.36.1-0ubuntu0.20.04.0
ProcVersionSignature: Ubuntu 5.13.0-27.29~20.04.1-generic 5.13.19
Uname: Linux 5.13.0-27-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.21
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: XFCE
Date: Mon Jan 24 16:19:33 2022
InstallationDate: Installed on 2021-05-17 (252 days ago)
InstallationMedia: Xubuntu 20.04.2.0 LTS "Focal Fossa" - Release amd64 (20210209.1)
InstalledPlugins:
 gnome-software-plugin-flatpak N/A
 gnome-software-plugin-snap 3.36.1-0ubuntu0.20.04.0
SourcePackage: gnome-software
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.cron.daily.apport: [modified]
mtime.conffile..etc.cron.daily.apport: 2022-01-10T23:09:37.086519