In addition to activating it in Winterboard, you also have to "turn it on" in your Settings.
Go to Settings > General > Keyboard > International Keyboards > ...
Speaking as a person living in the USA, I then select English and I am provided a list of versions to use (QWERTY, AZERTY, QWERTZ and then the 3 5-Row alternatives: 5Row, 5Row-Alt and 5Row-Numeric).
I am unsure what exactly a non-English person would do (or one not living in the USA), but, hopefully, I've got you in the general area.
Good luck and let us know how you get on.
Marilyn