gnome-panel in gnome-flashback-metacity session does not update time, indicators ; unable to click on gear button

[Norbert]

Steps to reproduce:
1. Install Ubuntu 17.10
2. Install `gnome-panel` and `gnome-session-flashback` packages
3. Reboot
4. Login to GNOME FlashBack session
5. Do some work (the last I did was `sudo dpkg-reconfigure keyboard-configuration`)

Expected results:
* gnome-panel is responsible, updates time, user is able to click on indicators (network, keyboard, bluetooth, battery, clock) and on gear button

Actual results:
* gnome-panel reacts only in left side (Applications menu and Places menu), but not in the right side (indicators are froze, user is unable to click on gear button)

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: gnome-panel 1:3.24.1-1ubuntu2
ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4
Uname: Linux 4.13.0-16-generic x86_64
ApportVersion: 2.20.7-0ubuntu3
Architecture: amd64
CurrentDesktop: GNOME-Flashback:GNOME
Date: Sat Oct 21 17:52:54 2017
GsettingsChanges:
 b'org.gnome.gnome-panel.layout' b'object-id-list' b"['menu-bar', 'indicators', 'show-destkop', 'window-list', 'workspace-switcher']"
 b'org.gnome.gnome-panel.layout' b'toplevel-id-list' b"['top-panel', 'bottom-panel']"
InstallationDate: Installed on 2017-10-21 (0 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20171018)
SourcePackage: gnome-panel
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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