New Dictionary not working with Android keyboard (Mi One Plus, 3.4.12)

Nov 12, 2012
Device is Mi One Plus.
MIUI version is 3.4.12.
When typing using the keyboard, the dictionary does not appear to be active, i.e. no suggested words are offered apart from contact names, all typed words are underlined in red.
Language is set to English (United Kindom).
Android spell checker language is set to English (United Kingdom), look up contact names switched on.
Personal dictionary appears to be empty.
Keyboard is set to Android keyboard (AOSP).
Auto correction set to Modest.
Show correction suggestions set to Always show.
Suggest Contact names set to on.
Next word prediction set to on.