How do you click on the completion? If I touch the completion, it disappears. It works fine in the small keyboard, where the completions are clickable buttons at the bottom. But not in the thumb board, where it just suggests one completion.

The previous poster suggested to use the right side of the d button. That does work. Only downside is having to move finger far off keyboard.

Come to think of it, I'd like to cycle through possible completions as well in the thumb board.