While running the Orca screen reader, system hangs while gnome-control-center is open

[Jeremy Lincicome]

When gnome-control-center loads, my computer becomes inaccessible. To get Orca working again, I have to force close the app with Alt+f4. There are parts of the control center that I can use, such as the sound and VPN settings, only if I invoke them from the dash. If I invoke Wi-Fi from the dash or top bar, it is inaccessible.
Steps to reproduce:
1. Launch Orca by pressing Alt+Super+s.
2. Press the super key, and type "settings" into the search box.
3. After the settings screen loads, try to move around using Tab and Shift+Tab. Also try to move using Orca's flat review feature.
The commands for using flat review can be found at:
https://help.gnome.org/users/orca/stable/commands_flat_review.html.en
On a desktop, the Orca modifier is the insert key. On a laptop, the Orca modifier is the Caps lock key, if laptop layout is set in Orca's preferences.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gnome-control-center 1:3.28.1-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Fri Apr 27 15:44:35 2018
InstallationDate: Installed on 2018-04-27 (0 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180425.1)
SourcePackage: gnome-control-center
UpgradeStatus: No upgrade log present (probably fresh install)

[Sebastien Bacher (seb128)]

Thank you for your bug report. What do you mean exactly by the system hangs? You can't interact with the launcher, switch softwares, etc?
Upstream has a report about keyboard navigation not working in settings when orca is enabled, see https://gitlab.gnome.org/GNOME/gnome-control-center/issues/70 , but your issue is different?

[Jeremy Lincicome (w0jrl1)]

From an accessibility prospective, the system appears to hang. Orca doesn't read anything until I force close the gnome-control-center window. I'm blind, so cannot tell if anything happens if I move the mouse, or press Alt+Tab.

[Jeremy Lincicome (w0jrl1)]

Here is an audio demo of what happens.

[Launchpad Janitor (janitor)]

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

[Jason Earls (jde2010)]

On my computer, Orca tried to read part of the Wi-Fi settings screen before it locked up and exhibited the same behavior that was described in Jeremy's audio recording.