You might have attempted to replace the keyboard on your T430 and you broke the middle trackpoint button. Well, here is how to fix it.
Starting with the 30 series, ThinkPads got a new modernized keyboard and many poeple dislike it. Do not take me wrong, it is not a bad keyboard, but when compared to the older model, it has a plethora of issues. Luckily, it can be replaced with the classic 10–20 series keyboard.