Running 16.04, single-user system. I set up the right-alt key to be the compose key. It worked fine.
Next day when I rebooted my computer, the compose key was disabled so I went into Keyboard settings and reset it back to right-alt. It worked fine.
This morning I fired up my computer, tried to use right-alt as compose and the key doesn't work. Checked keyboard settings and the compose key is set to right-alt, rather than disabled.
I reset the compose key to right-control, that works. When I switched the compose key back to right-alt, it remained an alt key.
What's going on, and how can this be fixed?
Thanks in advance.