I am running 17.04 (X)ubuntu, upgraded from 16.10, and the issue remains. I am running a slightly modified Xubuntu desktop. I don't use any Ubuntu Unity indicators (like the Sound menu), but I have installed the Pulseaudio plugin and the battery plugin and also use both the notification area / system tray from the xfce4-panel and the xfce4-indicator-plugin.

Network manager gnome applet uses the indicator (which appears in the indicator plugin area), as does the Blueman applet. Not sure if Blueman natively supports this or if it's a Ubuntu modification, but whatever.

IBus should have a GTK3 indicator using Ayatana, right? I see code for it on the official github that has been there for a while (since 2015).

How do I make IBus use the indicator? I greatly prefer the indicator system and think it is an area where Ubuntu's homemade craft is great. I keep forgetting that left-click and right-click reveal different options (for the current input method and for IBus as a whole).

Any help would be greatly appreciated.