I'm running Ubuntu 20.04.5. Recently all of my system tray application icons (e.g. Dropbox, Discord) disappeared, and restarting did not help. When I run Dropbox or Discord from terminal, their outputs both include the following error (among a lot of other output):

libappindicator-WARNING **: 17:17:54.679: Unable to connect to the Notification Watcher: GDBus.Error:org.gnome.gjs.JSError.ValueError: domain.replaceAll is not a function

Similarly, when I run OBS or Talon (dictation software) from terminal, I get a related error:

QDBusTrayIcon encountered a D-Bus error: QDBusError("org.gnome.gjs.JSError.ValueError", "domain.replaceAll is not a function")

These programs all run normally otherwise, but I really want the tray icons back because some functionality can only be accessed from there. I searched up these errors but couldn't find anything useful.

Things that could have triggered this: the Software Updater recently updated some software, but I didn't pay attention to what was updated. Also, I only recently installed Talon. Both were shortly before the tray icons disappeared. I also use a GNOME extension/tweak called Icon Hider to hide some system tray icons, but I have been using that for months with no problems. Enabling and disabling the extension also did not solve the problem.

Does anyone know what might be causing this or how I can fix it?