I am a long-time gnome-shell user. I appreciate the simplicity and elegance it provides, as I prefer having a minimalist environment that still provides me easy access to the applications I use.

That said, just as with any desktop environment, I've still run into problems now and again. One that's been plaguing me since at least the 18.04 release is with display of app indicators, specifically those using legacy system tray APIs.

Normally, gnome-shell ignores these, which is suboptimal as a number of popular programs still use them (including Dropbox, Nextcloud, Keybase, Shutter, and many others). To integrate them into Gnome, Ubuntu provides the gnome-shell extension "kstatusnotifieritem/appindicator support" (via the package gnome-shell-extension-appindicator). When enabled, they show up in your gnome-shell panel. Problem solved!

Except that if you suspend your system or lock your screen, they disappear when you wake it up.

Now, you can get them back by hitting Alt-F2, and entering r (for "restart") at the prompt. But having to do that after every time you suspend or lock is tedious.

Fortunately, I recently came across this gem:

$ sudo apt purge indicator-common

This removes some packages specific to Ubuntu's legacy Unity interface that interfere with how appindicators are propagated to the desktop. Once I did this, my appindicators persisted after all suspend/lock operations!