Can't get custom autotext to work

For some reason I've never been able to get custom auto text to work on my s5. I'm using Smart Keyboard Pro currently, and have gone into settings/language and input/smart keyboard pro/text prediction/custom autotext and set up a test replacement, where if I type DOTTY it will insert ARFARF. Just something to try to get this working. It doesn't work in Chompsms, or Memo, or pretty well anything else. I can see that the custom autotext is set up properly (it looks like this: dotty->arfarf).

Has anyone got this function to work in any keyboard, and do you have any suggestions on how I can get mine to work?