IBus input method: Drawn and effective cursor position differ

1. Open a source file.
2. Place the cursor somewhere in the code.
3. Press Ctrl+Shift+U to show usages.
   The shortcut is intercepted by Ubuntu. Instead of triggering "Find Usages", a "u" is added to the code. AFAIK, this is a known issue.
4. Press Backspace a couple of times.
   The visible cursor and the added "u" do not move while the effective cursor position does change and characters are being removed from the editor as expected.
   Before:

   void myFunction|();
   

   After shortcut:

   void myFunctionu|();
   

   After backspaces:

   void myFu();   u|
   

5. Switch to a different window and come back.
   The cursor is in the right position again.

Cursors in editors should always be shown in the right location.