Summary:
After using autocomplete for commands (d-pad right on controller), text input doesn't work anymore. The only solution is to restart the game.

Steps to reproduce:
Creative single player
1 Press d-pad right to open chat
2 Type: /loc (on the on screen keyboard)
3 Press B to remove the on screen keyboard
4 Press d-pad right to autocomplete /loc into /locate
5 Press X
6 Press d-pad right to open chat
7 Notice you are unable to type any text
(when unable to reproduce the issue, a restart of the game might be required)

Extra info:
This issue doesn't seem to affect windows 10
The d-pad has a double functionality assigned both moving the selection and autocomplete, while moving the selection can also be achieved with the left analog stick.