I rarely use gnome-software, and on most boot-ups it is useless. However there is not an entry at start-up apps, not even after showing hidden startup apps. Also, I haven't found any gnome-software-related process from systemd-analyze to disable it with systemctl.
/etc/xdg/autostart/gnome-software-service.desktop and remove the line
false. Then GNOME Software should appear in your Startup Applications list. You can disable it from there.
If GNOME Software still doesn't appear in Startup Applications list following the suggestion above, follow the steps below.
Open the copied
.desktopfile with a text editor and remove the line
Now GNOME Software should appear in your Startup Applications list. Disable it. Alternatively, you may append an
line to the copied
From https://ask.fedoraproject.org/en/question/92941/how-to-stop-fedora-24-gnome-software-auto-updating/, try these two options:
Disable it in gsettings
gsettings set org.gnome.software download-updates false
If that fails .. mask (disable) the backend service, PackageKit, the service used by Gnome Software.
sudo systemctl mask packagekit.service