QtCreator does not get keyboard input after startup

I do the following:

1) Start Qt Creator
2) Open a project (using mouse)
3) Open a file (using mouse)
4) Click into the editor, activating the editor and moving the cursor.
5) I type something using the keyboard

Result:
No text appears

Expected Result:
The text I enter via the keyboard appears.

Clicking into any other application running and then back into creator results in the keyboard input appearing as expected.