The integration between IBus and GNOME seems not to be complete on the Budgie desktop. This is a way which works:
* Don't add the input sources via Region & Language, and don't bother
with adding the keyboard layout indicator.
Instead:
* Open IBus Preferences via the terminal command ibus-setup
* Check the "Show icon on system tray" option
* Switch to the "Input Method" tab and add the input sources you need
from there
Then you can use the IBus icon in the top panel to switch between all input sources, both XKB keyboard layouts and IBus input methods. From there you also have access to configure respective IBus method.
The integration between IBus and GNOME seems not to be complete on the Budgie desktop. This is a way which works:
* Don't add the input sources via Region & Language, and don't bother
with adding the keyboard layout indicator.
Instead:
* Open IBus Preferences via the terminal command ibus-setup
* Check the "Show icon on system tray" option
* Switch to the "Input Method" tab and add the input sources you need
from there
Then you can use the IBus icon in the top panel to switch between all input sources, both XKB keyboard layouts and IBus input methods. From there you also have access to configure respective IBus method.
HTH