Notifications tray loses most of its icons if panel is restarted mid-session

[kode54]

If the panel is restarted, such as by reconfiguring the applet order, or adding or removing applets, then most of the notifications tray icons disappear. At least Steam manages to replace its icon, but none of my other apps do. This includes: Solaar, Vesktop/Vencord, Bitwarden, and Signal Desktop.

[WatchMkr]

This seems to be related to how some app indicators work. To reproduce:

• Launch Slack and Mattermost flatpaks so their indicators show up
• Launch Solaar
• In Settings, move an applet in the panel

Slack and Mattermost app indicators disapear. Solaar is still there (Solaar doesn't show the icon in the tray at start or after moving an applet)

[ids1024]

Chromium/Element does have code in https://github.com/chromium/chromium/blob/main/chrome/browser/ui/views/status_icons/status_icon_linux_dbus.cc to handle NameOwnerChanged and register the status notifier item with the new StatusNotifierWatcher, but it doesn't seem to work perfectly.

Testing with Slack:

It looks like the if cosmic-applet-status-area is not running before Slack is started, when cosmic-applet-status-area is started, it does not register the item.

While if cosmic-applet-status-area is running before Slack, and re-started while Slack is running, it re-registers the item with the new instance.

But it seems to be very unreliable at re-registering if cosmic-panel is restarted, rather than a standalone cosmic-applet-status-area process. This may be a race between the instances of cosmic-applet-status-area on different monitors? If the one hosting the StatusNotifierWatcher is killed first, the other one may try to take over as the StatusNotifierWatcher, and I guess that being killed may race with Chromium in some way that prevents it from registering an item on any future StatusNotifierWatcher?