不好意思,回答自己的问题:
In Fedora MATE, I have to go to Input Method Selector, select ibus, then log out and re-log in. Problem solved!
In Fedora Gnome, once I start the ibus-daemon, it appears to be automatically selected. No need to go thru the above step.
请参阅:
https://forums.fedoraforum.org/showthread.php?p=1793007#post1793007