Closing ubuntu-software on an app page then prevents returning to main (all) page

[Doug McMahon]

Test Case:
Open ubuntu-software, open page for any app.
Close ubuntu-software from that page.
Re-open ubuntu-software, it will open on the app page you closed on.
Click the back button, nothing happens.

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: ubuntu-software 3.30.0-0ubuntu1
ProcVersionSignature: Ubuntu 4.18.0-8.9-generic 4.18.7
Uname: Linux 4.18.0-8-generic x86_64
ApportVersion: 2.20.10-0ubuntu11
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Wed Sep 26 23:49:40 2018
InstallationDate: Installed on 2018-08-24 (33 days ago)
InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Alpha amd64 (20180822)
InstalledPlugins:
 gnome-software-plugin-flatpak N/A
 gnome-software-plugin-limba N/A
 gnome-software-plugin-snap 3.30.0-0ubuntu1
PackageArchitecture: all
SourcePackage: gnome-software
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Olivier Tilloy (osomon)]

I can reliably reproduce the issue on my laptop running up-to-date cosmic.