I have iBus with Sanskrit (IAST) and Bengali layouts. Besides that I have English and Russian keyboard layouts. iBus works in other applications (Firefox, Thunderbird), but doesn't work at all in Writer, Pluma, SublimeText, Atom etc. It used to work some weeks ago. Any suggestion?
Have you switched to Lubuntu? Maybe you could have some trouble if you have got it. Moreover maybe you have installed some apps that have deleted some libs linked to ibus. Remove all with
Re install from beginning.
Another thing to check